If you are in the UK, then JP Books in London sells all these graded readers:
http://shop.jpbooks.co.uk/en/textbook-reading/7970-level-betsu-nihongo-tadoku-library-1-level-0---japanese-graded-readers-wcd-vol-1-level-0.html?search_query=graded+reader&results=13
As I said above, Japanese Amazon or CDJapan are cheaper, even with shipping costs added on (assuming you don’t go for the most expensive options).
Yeah they are! I was browsing through their Genki textbooks and just left after I saw what they were charging lol.
Adanami in London has manga really cheap, though they are cash only.
I started with Level 2, which are not particularly difficult. I think someone with N5 skill should probably start there. If it is too hard, then maybe try Level 1. I would skip Level 0 - they look too easy, especially for what they cost.
I’m working on Level 4. I do enjoy both Level 3 and 4. 4s are challenging for me N4 skill level. The packs call these intermediate level - N3 to N2 level, but this seems to be overstating the level needed a bit. Either that or I am selling my own skill short a bit. Considering the included CDs for listening practice, I think they are worth the asking price if ordered from Amazon.co.jp. Don’t order the whole set from White Rabbit - that price is just insane. If you order them a few at a time, it won’t feel like too much, then maybe sell them off later.
I would also recommend the Magic Tree House series of light novels. The grammar used is pretty simple overall - but they will be challenging - I will call them “Level 5 Graded Readers”. The amount of vocab used is very large compared to the readers, so you will need to stop and look up stuff constantly. I like them better than Yotsubato because of far less colloquial language used and far more material for the money.
Yes, thank you! Now I am starting to get the idea of what Japanese grades are there in the wild = )
I have bought Lv1 and I have found it too easy. Lv0 looks uninteresting to me. Now, I am waiting for the end of this month to buy Lv2. I might try to look into Lv3, to see if I can read it or not. (I might not be able to read it, though.)
Since there was nothing else out there on the market like them, I’m starting to disagree that they are over-priced. I guess the first level sets (level 0) are maybe, since they are quite short (although they come with 6 books per set instead of 5). But the beauty and uniqueness of them, the CD for listening practice, I honestly think they’re great. Also, most people lose interest or time or give up after the low-intermediate level, so it makes sense to have the lower level books the same price. After going the naughty route to get them, I decided they were worth paying for in the end. 
I also loved the Tadoku graded readers which are almost as pretty and go up to level 5 (but audio is online only) and bought them as individuals, but they are now only available in sets which sometimes include books from a variety of the levels, which I find quite annoying.
The Oxford Brookes graded reader books are also very nice (no audio). With those, I think Level 1 is slightly harder than the JGR level 1 books and each book (with 5 or 6 stories) is quite a bit cheaper than the JGR (but remember, no audio!).
There are other options (here and here), so it seems odd for me to say, but I still think the White Rabbit Press books are good value.
Thanks a billion. As a person with no income, this stuff is out of reach for me unless someone buys it for me as a present, generally. Although I do have some nifty books + audio that aren’t graded readers that I’m super interested in getting and hope to eventually save up for (plus they’re cheap). I think they’re a tad bit above Graded readers 0 and 1, but having no experience with those, I wouldn’t know. 
I also enjoyed lvl 3 stories, it’s just that after a while the style can feel a bit plain so I moved on to Yotsuba (with some difficulty). That said the quality is high and there are always things to learn, plus you get to know about real Japanese folklore.
There’s also this:
http://hukumusume.com/douwa/pc/100monogatari/index.html
In my mind they are not too expensive, like you say it’s pretty unique series for Japanese learning which allows them to charge more.
The biggest thing that makes them seem slightly over priced is that English graded readers can be found cheaper. But the market for learning English is much higher, so go capitalism!
I have two:
vol.3 15 落とし物がいっぱい
vol.3 16 東京の電車
Here are other legal resources you might consider:
http://www.hukumusume.com/douwa/0_6/1nen.html
http://kyouzai.u-biq.org/
http://watanoc.com/
https://matome.naver.jp/odai/2138794543196592401?page=1
* https://www.koipun.com/reader *
* https://satorireader.com/articles/news-neko-densha-edition-m *
http://mykikitori.com/
http://life.ou.edu/stories/
http://dl.ndl.go.jp/info:ndljp/pid/1168917
* https://librivox.org/search?primary_key=0&search_category=author&search_page=1&search_form=get_results *
http://hukumusume.com/douwa/English/index.html
* http://www.yomimaru.com/ *
* https://www.dropbox.com/s/k0ewao7a65it2h4/chokochoko%20collection.pdf?dl=0 *
It is a bit of mix-up, i hope you find something useful :).
The links with * are worth checking out.
There used to be ChokoChoko-colection pdf and it was great. Will edit as soon as I find it Found it 
!
I have a set that’s super easy! Picked them up while I was in Japan though so I’m not sure how easy they are to get here, but it’s all about a corgi and his owner from the Corgi’s pov.
I’ve found a few ‘western’ children’s books in Japanese book stores in Japan (Or Kinokuniya in Sydney).
Whilst they aren’t brilliant for learning perfect Japanese, they are translated as best as they can, and because I already know the stories it’s easier to infer meaning.
And I only sometimes get strange looks on the train as I (note the beard in my photo) read 'The Very Hungry Caterpillar" to my wife on the train to work in Japanese.
Do you put on funny voices too? 
Even if he doesn’t, he probably should now! : )
I have never said this before.
“I can’t wait to go to work on Monday”
Do you have an ISBN for those?
I went looking for them too
Here they are on pixiv: https://comic.pixiv.net/works/1228 Links to the books on amazon.co.jp at the bottom.
After having looked for precisely this a few weeks ago and scouring the net for what I felt would be the best content for my money I ended up settling on this:
It’s a translation of an english book, which might not make it seem like the ideal book, but the thing is - it’s simple. It’s not absurdly simple so if you have no grammar knowledge this won’t be the book for you, but I’m on N4 level and I can understand most of the grammar in it. There’s plenty of vocabulary I don’t get, so I have to read this with takoboto at hand, but that’s okay - I get to pick up some vocabulary on the way, which is fine. That little book has over 157 pages of text (okay, text and images, but still) for less than $10 meaning there are few things you could better spend your money on as long as you’re on the right grammar level for it.
Other than that, I’ve seen this one recommended too:
But I haven’t got it myself since I didn’t have enough money for both (I was already getting several text books). Still, maybe someone here has read this latter series and can let us know how easy to read it is and how entertaining.