Ask the guy if you can meet him somewhere and take it for a test ride. You wouldn't buy a car without test driving it first, would you? The same should be true for a bike. You may fall in love with it before riding it, but then when you do ride it you may find it too uncomfortable or too big/small/heavy... whatever. But don't rule out the Cannondale. You can get a custom fit on it since it's at a bike shop. And don't assume they won't be open to negotiating with you on the price. I bought my Giant mtb from a bike shop and ended up paying almost $200 less than sticker price. So it is possible. Ride them both and then decide. Good luck!