I bought my SC-1 new on ebay for $145 shipped about 3 months ago, though that was a little high, I thought. They go for about $99 on ubid, I think. Somewhere around $120-ish would be fair I think?
Probably would be better to get more opinions though...
Crutchfield is marked up (around 200 percent I think) just like Best Buy or a Circuit City. With ebay or ubid you are cutting out alot of that profit by skipping the large corp. middle man.