Thank you guys for all of your comments. Everyone has great comments and pros and cons that I will seriously consider. I do realize that it would definitely be risk (just like purchasing any horse at any age is) and I will definitely have a good prepurchase exam etc. Actually, the horse I am thinking about is a rescue that I can foster first and take care of then I would have first choice to adopt. If/when I foster her they rescue pays for vet bills until someone adopts her even though I would be sponsoring her board and paying for her feed and providing her care. They full assess the horse for riding suitability and health needs. I do trust them and feel that by fostering her first I would get a better idea of any health issues, etc.
I am prepared in the future-- if she does not have any immediate extreme health issues that I feel I wouldn't be able to fully be able to take care of or that would be a good fit for what I am looking for--to be able to give her a retirement home. For the next several years one . Horse would be my main focus until we buy property again with acreage. For now boarding is my only option but we do plan on owning acreage when we buy our next house. I have owned a horse in the past so I do understand all that comes along with owning a horse young or old.
I appreciate everyone's opinions because I don't want to think that I was totally crazy for considering an older horse. If I do decide to foster her I am sure I will post lots of questions and concerns I have so I make the best choice for her and me.