Are the GRE books and aids worth it for a poor starving math major? I’ve heard they don’t help at all and they are the best thing ever from various people.
I don't think they're worth it. There's plenty of free material on the GRE website. If you use all of it, I can't imagine needing more, or even wanting more.
You can check books out from the library too. I think, beyond knowing the format of the test, (which you can do free) the only thing aid can help is vocabulary. For the SATs I had a "word flash" book that was cheap and cool.