$20 to play in a PDGA sanctioned event is a lot of money? If that's the case, I wish the PDGA sanctioned events in my area were as expensive as yours were.
Seriously, I play MA3 and the PDGA tournaments in SoCal are never cheaper than $35, more like $50, sometimes higher. But there's always a players pack with at least a nice $15 disc, usually more. So, in your case, I think it's not completely outrageous to only be playing for a trophy. Although, I would be shocked if you don't receive some kind of player's pack too.
Personally, I like winning a trophy and I like receiving a nice non-dri-fit shirt with a cool design but in the end, couldn't care less about any of player's pack nonsense. I pay my $ to play PDGA tournaments for the competition & the action - that's it. And, as far as I'm concerned, I've gotten my money's worth of that x1000. One of the best values I've found ever.