I do not own a 210 model, so I don't know of any issues with that model specifically, but there are a couple things to check with any used RV purchase. Unless it has been abused, a 2007 model should still be in great condition, just go through and open all drawers, raise and lower blinds, anything that moves, opens, closes, etc, try it out to make sure it still operates properly. Inspect the tires, make sure they not only have good tread and no blisters, but also look at the date stamp to make sure they are still in their life span. Trailer tires have a shelf life, you don't want to be traveling on old tires.
If you are not sure how to read a tires date stamp, click on link for info...
Check the shower surround to see if has warped and pulled away from the wall, that can lead to water damage later on. Most items you will find wrong will be easily repairable, and you can use them to negotiate a fair price.
Good Luck on the purchase!