It ended at a pretty good price, despite the crackes seat-tube.

As redxj mentioned, GT GTBs have been selling like hotcakes on eBay lately, I guess a trend has started. They never used to come up but I have seen 6 in the last month, one in pristine condition ended the other day at $610 for just the frame/fork. It is a ridiculous price if you ask me, that is why I never follow trends (or at least try not to).