Depends really what you like. For me I enjoy collecting cello and wax packs, proofs, and stuff from the 80's and early 90's when I was a kid. I would never really recommend collecting for the sake of investment, as that bubble has come and gone (but who knows?). You should collect what you like and what interest you. If breaking boxes is your thing then the good news is there is plenty of product to choose from. Usually you will get what you pay for, but you usually never get your money back...if that makes any sense.
Look up cards infinity on youtube and look at some of their box breaks in order to get an idea for what you can get for various products.