no kidding!!
Our vex teams have always had a $200 limit on extra parts, in fact, this year our in-house at our in-house vex competition, my team used less then $50 dollars of actual vex parts. I happen to have a large supply of Erector Parts that supplement the base kit very nicely. The only parts I end up buying are usually more motors. I believe this makes it more challenging to design a robot.
On an FTC note Our team has the additude that for $900 the kit needs no supplemental parts, and the only thing we have ordered is another motor controller.
(I beat you Rick TYler)