Many variables. If you find a quality unit that has been used by someone that cares, with full service warranty, its one thing. To buy one without records, you are buying into a******shoot.
About every five years, you replace all fluids. That is 10-25 gallons of anti freeze, Transmission fluid, power steering fluid, differential fluid, new air dryer dessicant, two fuel, one oil, one trans and air filter. Replace all belts and hoses. I won't put a dollar amount on it but it is thousands.
Six tires are running $3500-$4000.
Don't forget about the genset.
I have looked at quite a few Foretravels and they seem to fit the profile of having prideful owners who have had other brands, finally bought a good one, and really took care of them. I wouldn't hesitate to buy a well cared for Foretravel. Although they have had a few issues here and there; bulkhead separation, etc.