Too many miles for a V10? Not hardly if normal maintenance was performed. If they cannot give you maintenance records, assume that you will have to replace the coolant lines (and coolant of course), all fluids, Drive Belt etc. You said the motor "looks" good but how is it running?
Also, like Bumpy said, the roof is likely at the very end of its life (ours sure is).
The price is decent for a slide model but I would certainly try to get it for less. There are so many factors but I wouldn't run from a V10 with only 98,000 miles on it.
