"How much should he expect to
"How much should he expect to pay and how much will the dealer want are two different answers.
The fact that it only has 53 hours on it and it's now 8 years old (model wise anyhow) tells me that it has sat neglected most of it's life. If the previous owner used it on average less than 7 hours a year, they probably didn't have it into the shop for all it's recommended service and there's a good chance that it still had it's original oil/filter on it along with the plugs, impeller and who know's what else.
If the dealer is willing to throw in a warranty in writing for at least 6 months, I may consider it's value at 800-1200 bucks - but even then I would probably shy away from the deal.
4 strokes are not like 2 strokes. You neglect a 2 stroke and it still runs for you - neglect a 4 stroke and you have a couple hundred pounds of scrap aluminum (which has taken a dive in price too lately)...
I would be very, very careful with this deal..."