WaniKani has a sale around Christmas time where subscription prices are significantly lower. (I used it to convert my year subscription into a lifetime subscription last year.) I recommend focusing on finishing the 3 free levels first, then worry about paying later.
When I started with the free levels of WK, I did a lot of research to try to find out how good WK was, how fast people complete it (speed run vs slower pace), which subscription tier they picked, etc. I really thought that I had everything figured out, but reading someone’s experience VS experiencing it yourself are very different. (EX: I thought I could speed run, which I did in the beginning, but “life” kept happening to me/slowing me down.) In my opinion, there’s a big difference in difficulty/workload between 1-3, 4, 1-10 (Pleasant levels), and 11+ (Painful levels).
I really like WaniKani even though I passed N2 recently and already know a lot of the kanji. I read Heisig’s “Remembering the Kanji” in the past, but it doesn’t teach pronunciation. WaniKani has a lot of funny stories to help remember radicals/kanji/vocab/pronunciation.
There are free alternatives such as Anki decks with mnemonics similar to WK, but the thing that I enjoy the most from WK is Third Party API. The add-ons you can get make WK even more fun/easier to use. My top favorite ones are WK Dashboard Cockpit, Back To Back, and WaniKani Show Specific SRS Level in Reviews. But there are many more that affect the appearance and information of the dashboard, lessons, reviews, and forum.