To answer your question, I only have one bike, but it does have 650s. It was custom built for me by a friend. We bought a no-name frame (Tsunami) from chucksbikes.com and then he used parts that he had, plus other new parts and voila! The frame has compact tri-geometry, but it's really set up as a roadbike. And it's a 52cm. I love it. And it was dirt cheap. I only paid about $650. It was less than $200 for the frame. My components are all high end Shimano (Dura Ace and 105) but my friend gets the parts at cost, plus he had some "extras" lying around. It would have been over $2K from a shop.
But the moral of that story is, if you can build a bike or have a friend who could, you could probably do it very cheaply with used parts.