I had the same problem as you when i started, i'd say collect stuff that you enjoy and can mainly afford, i had a heap of pc's when i started but in the end i settled on a Gordon Hayward and Tristan Thompson. One because i thought they were reasonably cheap and they were both young with a lot of potential. Settling on a PC doesn't mean you can't get other players. I personally think having 1 PC is the easiest because you can have more cards of that 1 players and it you may get the top range of cards for him.
I definitely agree with all of what Whitey said especially considering we are the youngsters of the collecting arena , spend mainly on 1 player and than spend a little on another player
I think once you have a PC at a certain point you can start another. I got my JR PC to the point where I pick up the odd card, even base every now and then. So I started my Kobe PC, plenty out there, a good challenge.
Yeh thanks for the advice norm, I picked mayo coz I like him as a Player, Drummond already have 1 auto and I love him and Kemba is one of my favorite player