時間がたつほど価値が上がる roughly means, “as the time goes by, the price goes up”
On the other hand,
物が増えればふえるほど整理が大変になる roughly means, “If the things increase, to the extent of the increase, it will become that difficult”
In essence, they are like the book says the same thing in English, but I’ve asked a friend of mine about ~ば~ほど, and he told me that that form is not often used in conversation because people to tend to rephrase their thoughts differently using fewer words. Which form is better? I couldn’t tell you, but after finding out about just using ほど in that way, I prefer not to use the ~ば~ほど form. To kind of answer your question, you could convert all of those examples to one form or the other. I believe the grammar text just wanted to show you how to use them both just using a couple of examples. I believe for the sake of clarity you would probably need to use ~ば~ほど in its entirety, but I am not fully confident about that though.
Awesome thanks for this explanation. I find this issue in textbooks a lot, when they give you examples of two different ways of doing something and then don’t clarify if there is some kind of difference or if they are completely interchangeable.
I’m guess kanzen master N3 book is assuming the reader already understands the basic uses of ほど and is just covering another way it might show up on the test.