Going rate on a rex seems to be around US$150-175 plus shipping. If you have a 690fsb validation, you might be able to get US$200-ish.
Here's one that sold a couple days ago for $168 incl. shipping: http://www.ebay.com/itm/ASUSTeK-COMPUTER-Rampage-Extreme-LGA-775-Socket-T-Intel-Motherboard-/141863398883
Edit: Note there was only 1 bid on that one so that price is pretty soft. With the LET and faulty switch (but without 690 validation) would think you're looking around Random's estimate.