Seems like an awfully low price, but NADA book says that is about right for a very-low mileage 97 Mirada. Over $2000 uplift for the very low miles, so a typical price for one would be $7500.
The Mirada is a very inexpensive unit to begin with, so don't expect frills or top quality construction. Insulation is likely to be minimal, nose and vibration relatively high, that sort of thing. It's a weekend getaway machine, not a fulltimer's home.
A little used motorhome can have problems with anything rubber - belts, hoses, etc. And tires are probably old, even though they look good. Check the dates on the tire sidewalls to be sure they are recent and not 7-10 year old tires that look new.