Once you've found the car you're looking for, check its description, as you would for any eBay listing, taking particular care to note the price, sale type (auction or Buy It Now), the condition, ...
As a one-of-one car, the C1000 has been pretty easy to keep track of. It was for sale on eBay Motors for $350,000 when we last saw it in 2006, and we've even located a 2011 video of the car ...