depends on where you are, of course. I wouldn't pay more than $200 for it, especially with biopace. Your mileage will vary, of course. If looks to be in pretty good shape. It also looks to be pretty big, like rider height = 6'2" or so...just a little heads up. Plan on at least new cables and tires...maybe replace that ass hatchet seat as well.
He put it out on CL when I balked at a straight trade. Even though I showed him the pages direct from the '87 catalog he is listing it as an early-to-mid 90's model and asking $300. Told me the LBS tech offered him $200 for it last year.
I'd be surprised if he sells it for $300. They do sell for between $200-$300 on ebay, depending on components. Are those 105? I sold a '93 with RX100 components for $225 last summer on CL in the NYC metro market. But I had completely overhauled mine.
Mine was also red, which I think makes an easier sale. Baby blue just isn't very fast looking and those graphics..well...
if you call cannondale, i think the number is 1800bikeusa, with the serial number, they can tell you the exact size and specs, and year it was made. i think all cannondale roadies went to STI's in 1992. $200 is fair id say. on teh high end of fair. $150 would be a more fair deal for the buyer though. check the frame for hairline cracks at the welds on teh rear dropouts, they aren't the kind prone to it, but always check. i always loved that airbrush zigzag they did for 2 years