I had a caliente a few years back - similar frame design. They are excellent tri/tt bikes - the company and Dan Empfield (founder) are the ones who pioneered tri geometry. It is more aero inspired than wind tunnel tested, but has the right elements. I recall internal cable routing to be a pain, so don't remove any cables thinking you'll quickly replace them if you get it.
It's now a dated design compared to recent frames so I'd except a big decline in value. If it's used 105 and a basic used wheelset with signs of wear etc., I wouldn't offer more than 40% of original price and start at $600ish. I'd expect to find a frame on ebay similar to it for $400 or even less and used 105 has little value.