On the one hand, that figure wasn't nearly in as nice shape as yours.
On the other hand, that may have been seller's asking price, and he may have taken a best offer in the 100-200 range.
Still, a great find and probably one of the nicer ones I've seen. I have two loose ones myself, both slipped through the cracks on the 'Bay as well and both obtained within the last 9 months or so. They have some paint loss on the goggles/nose, one doesn't twist well at the waist, other has a loose leg but still stands - thus, "played with" condition for sure and not as nice as yours but display REALLY nicely.
On a related note....