No. Not worth it. I would have to know a lot more about the condition of the paint, what model and age. The Suntour RD with SORA brifters makes this a Frankenbike.
The wording on the ad makes this guy look like a huckster to me. "CANNONDALES START in the thousands!!" Give me a break. 7 speed Cannondale is probably early 1990s with newer brifters added later.
The cantilever rear drop outs are a give away that it is an older Cannondale (that style frame came out in 1989). It has canti brakes. It could be a drop bar conversion of a hybrid, or possibly a touring bike. I do not see one in this color combination. Maybe its a repaint?
Cannondale logo on the top tube makes it 1990 or earlier. That is the period of sucky paint.
I sold a seven speed Cannondale (1991 R600), all Shimano 105 seven speed, with SORA brifter upgrade, for $320. That price was full market IMHO. Bike was in great condition.