Just a thought most of the stuff TheExpert wants are already available. The real problem is maintenece. Models and textures last a while but scripts often times don't last much past the next update.
Persoanlly I don't see the point of buying "place holders". I make several bmaps with small written numbers or letters on them to hold places while i'm coding. It's free and usually takes less time then it would to buy and download them.