You're worried you paid too much and maybe you could have gone with a backyard breeder?  Let me tell you a story that should make you feel better.  I'm in North Dakota so we don't have a lot of breeders in our state.  When I wanted a Maltese puppy the only place I'd seen them was in a pet store.  The pet store got two females from a breeder in the area.  Well, I wanted one badly so I bought the smallest, cutest one.  She ended up having three knee surgies for luxating patella (or what ever the slipping knee cap is called), and a hernia surgery.  My husband calls her "the girl with the two thousand dollar legs"!  She has the best temprement of any dog we've ever had and she is priceless to me, but I couldn't check out the parents so I didn't know if there were bad knees in the bloodline or what.  Count yourself lucky to have found her.  She is adorable!  You only live once.  Don't worry about it!