WOW 7,000 is a LOT of hours.
With that said, if it has been serviced correctly the hydraulics/hydrostatics should be fine. The only concern i would have is the engine, diesels usually do about 6,000 before they start to get hard to start. Another note is if you leave the key on the hour meter will click over happily, even if the engine is not running. Hours are always meant as a guide only.
If it starts easily, smoke clears up quickly after startup and has enough power to spin all 4 wheels if you push into a pile of dirt or push against a large tree. Ensure when you start it the engine is stone cold, put your hand on it to be sure. If the engine is warm you don't get a good idea of its condition.
$5000 to me sounds like a good price.