Hi Sara and welcome to the group....
As there is a bit of a weight
difference in 13's depending on make, year and if it has a bathroom, you might tell us what you will be towing with to better aim your search.
Egg's in ready to go condition, and that are bargain priced, usually only last a few hours if advertised, no matter where they are located. As such, you should also mention a budget range so you don't get showered with rigs out of your price range.
Good Luck and keep reading everything
FWIW, in the past year I have seen 13'ers sell for as little as $1800 (A Campster) to over $13,500 for fairly late model units.