
"When I was planning mine there was a a certain amount of time where the pup could be brought back for a full refund, once it was of an age where it's 'resell' value is less it could be brought back and once rehomed the old owner would get all the money the pup was rehomed for minus expenses incurred."
Thankfully I only had to get involved with this situation once. She was an older puppy who, once I had a litter from the litter sister of the dam, I decided this older puppy wasn't really as good as the puppies in the second litter. So I offered her for sale. At a reduced price obviously. Sadly that home didn't work out so I had her back and told them that I'd give them what I later sold her for, minus a minimal 'boarding' fee depending on for how long I had her before I found 'the right home' for her. They seemed ok with this and as it happened a perfect home for her turned up, quite quickly. These people then came back at me asking for ALL the money to be refunded. Clearly they'd been talking to others about what happened. I was just more than relieved to get her out of that first home - apparently they had a squaddie son who had been kicking a football AT her, scaring her to death, poor girl. This I'd not bargained for when I let her go.
In other words I'd always concentrate on getting a puppy back, above anything else.