If the fit and price are good I would say go for it.
I started shopping for an SL1 when Performance was still around. They were pretty scarce and $$$.
I found the best price from this shop:
http://www.bicycledoctorusa.com. He was quick to reply to my questions.
I stumbled on an Altamira SL that had been relisted a few times on ebay, for a fraction of the "new" SL1's price. Same C 15 carbon frame and fork material as the new SL without the price. The build quality is very good. It fits me well, built up light and rides nice. No issues what so ever.