information on 2000 Shasta 25' Cheyenne Cl C

Regardless, physically check the rig for any evidence of water damage. See any, run. That is the first rule of buying used.

I second the suggestion to check out Nadaguides RV for an idea of a realistic price. I did; even with no information other than what you provided, it looks like *$8,000.00* is a lot more in the ballpark than $18,000.00*. JMHO, but the purchase of a 16-year-old, entry-level when new, low mileage (not necessarily a good thing in a rig that old because it means that it has done a lot of "sitting", and a "sitting rig" deteriorates faster than one that's used), unknown coach/systems/engine condition motorhome is not something I'd do without a LOT more research and condition checking.

There is no slide on this RV

I would give a look at NADA for starters on a price. You did not state if the model you are looking at has a slide.

At this age the condition of the "house" portion of the RV is much more important than mileage and mechanical condition. Price sounds high for the age but if the house portion is solid with no evidence of leaks and all appliances work it could be worth that much.