No, your expectations may not be too high...
.. if they are trying to sell you a 7 year old Jay Flight, and it turns out to need the bearings repacked, new tires, caulking/seals could need to be replaced, refridgerator may be ready to give up, awning may stick or is worn, etc etc.... and they want $3000 more than NADA avg, that trailer could wind up costing you a lot more over the next year if it has really seen more use than anyone really knows.
Go online and find a checklist to take with you. Try to anticipate the things that look "tired" or that you know for sure will need replacement soon. Figure the cost of what you will need to put into the tt once you take it home. It may be that you shouldn't pay more than the NADA quote.
Google "check list" + "used rv" for detailed lists you can take with you when checking out any used rv.