Worth is a tricky thing. Price is simply set by supply and demand. They don't make the X anymore, so if you want one, there is a rather fixed supply out there, and the shift to a different satisfaction curve is a big jump (other boats of similar nature). But with a down economy, probably an excellent buyer's market at the moment.
But if you want a powersailor and like the X, it could bring far more worth in terms of enjoyment to the owner. It might be a good thing if the boat hasn't been modified much. Other than the few gifted artisans that mod their boats, many mods may not be well done, or what you might want. For example, I have a 4 inch smoke stack on mine. and an inside secondary steering wheel by the galley. Probably would not help the resale value.