Definitly do a test ride. Just some advise but you should do what you plan on doing with the horse. If your going to trail ride, take it out on at least an hour or more trail ride. If your going to jump, take some jumps with you if they don't have any and do some jumping.
We just trail ride, but the girls we have now we took on a 4 hour trail ride before we ever started talking money.
"Until one has loved an animal, part of one's soul remains unawakened..."
- Anatole France