I did exactly this -- in 2013, I bought a 2007 Prius w/ 100k miles on it for $7k. I LOVED that car. It's practically a pickup truck. I hauled stuff. Moved furniture. Camped in it (Google "Prius Tent"). Drove halfway across country and back for something like $100.00.
Absolutely one of the best, most useful cars I've ever owned. I ran it up to 180k miles and then gave it to my son who is in college. It's still going strong for him.
I plan on picking up another one in the near future. If this is a near-even swap for you, price-wise, then do it and don't look back.