Sounds like a "Banging " deal (as my students would say). Go down to you local Cannondale dealer and try a 54cm frame. I have a 31" inseam and ride a 54cm frameset, but all manufacturers are different. It may be that this is just the size for you. Everything else makes it seem to be a great deal. I ride the Elite wheels and have found them to be a real find. Light and very rugged. Only thing that would make it better is if it were Campy equipped rather than Shimano. But as stated above. Unless you know it is your size, don't buy it just because it is a good deal (which it appears to be).
I have purchased five bikes off of eBay over the past five years and have always been very pleased with them. Is the only way to buy, in my opinion.