I started playing and collecting in 1993. At the time I didn't know what to collect so I collected anything interesting. Within a few years my interest narrowed so that I sought out those discs that I most wanted to throw. So every time I picked up a new gem I hoped it might one day make it into my playing bag.
I realize now, that for maximum collecting value (which I don't especially care about), I made at least two mistakes. (1) A disc which is older and rarer has greater dollar value than a disc which actually flies better. (2) A driver is worth less than a putter or midrange (my hundreds of cyclones, x-clones and banshees-primary drivers in my game over the years-are worth little now)
The disc which I actively throw and collect is the Discraft Rattler. I have plenty of goodies to trade.