Jenn,
I assume you're in/near Seattle... if so try asking the question to
http://www.seattleminiowners.com/. They probably have a better idea of current prices, and most likely will know the car in question. Seek their advice/assistance... who knows, one of them might even offer to view it with you and go over it with their eagle eye

Based on the few photos you have, the car seems to be in good condition and "sympathetically" restored. The shell looks original and in good shape, but it sounds like the engine may have been replaced during the restoration (a newer 1275cc rebuild has been fitted???).
Note: The car is also advertized on MiniMania's site
http://www.minimania.com/web/id/9182/Cars4Sale_Detail.cfm... owner has dropped his price as he was looking for US$14.5k back in May. Maybe he's getting desperate to sell so that could be in your favour.
Price? Hard to say what to offer without seeing the car in the flesh. If it were me (and the car didn't have anything "odd" about it) I'd probably try to get it for about US$10K.
Regards,
Colin. (Santa Rosa, CA)