That doesn't sound like the way a clutch acts as it's heading south.
Universal is more likely, feeling vibration in the pegs is typical when they go. Or it could be the drive shaft and pinion cup are dry and ground up. Neither of those possibilties involve the engine. A new universal joint is about 70.00 if you buy it from Honda Directline. From the dealer lots more, plus that very expensive but highly skilled labor.

If the drive shaft and pinion are shot it will be more in parts and labor but less than a clutch would be.
The worst likely possiblity is the final drive spline gears are ground up due to lack of lube. In that case you might be better off to buy a used final drive from Pinwall. They list parts on Ebay but you can contact them directly.
It's a ggod idea to see the problem parts the dealer is telling you about. You can search for drive splines and pinion cup on this site to find pics of worn out parts so you'll have a better chance of not being BSed.