Can't go by "book" on these bikes. He could do at least a grand better on this site with only 550 miles. Worst case scenario you might have to do a quick carb clean - maybe just the pilot jets but maybe not if stabilizer was used. I already have one but I'd buy it just to have my next bike in reserve. So go make a deal!
KTM 950 SE
CRF450 flat tracker
Get on with riding or get on with dying - one or the other