Running, or not running?
Minor digging finds ads for that model that are claimed to run well, but with lower mileage, for $2400 - $3000, knock something off that for the real price as opposed to the advertised price, knock something off for known parts needing to be replaced (how old are the tires??), knock something further off for higher mileage. That's if it runs nicely. If it runs, but poorly, figure on a few hours for going through the carburetors ... expect to find more problems. If it's a non-runner, I'd pass unless it's so cheap that you could recover the sale price by selling a few parts.
I acquired a non-runner EX500 (same engine) for free about 20 years ago because it was dead as a doornail. Low compression due to seized/rusted piston rings. Pulled the engine ... removed cylinder head ... new piston rings, deglazed cylinders, new head gasket, cleaned fuel system, new battery ... had the bike tentatively sold before I had the engine assembled and running. We got it running well before the prospective buyer showed up. (He bought it)