Help, rescuing a Bernedoodle?

I purchased a mini Bernedoodle off of Craigslist for $800. He was so happy go lucky, charming, sweet, funny. He never bite me. However, my toy poodles were not fond him. They were pretty stressed about him. My other two male standard poodles absolutely loved him. He was fun to take out in public. Very well behaved. He wanted to say hi to everyone. He always wanted to lean against me and cuddle with me. He is a great watch dog. He was so happy with me. I was worried about my toy poodles stress, so I gave him for free to a family I thought were really nice people. However, they told me the Bernedoodle has been biting them and also very anxious and nervous. They said he is also fighting with their male standard poodle. This is so out of character for him. They have complained to me about him and all the trauma he has put them through. I tried to get him back a couple days ago but she held him hostage and is demanding $500 for him. Her comment was like no I am not driving all that way and giving him to you for free. You can buy him back for the amount I would have gotten for selling him. So I am planning to buy the dog back. For $500. For a dog I gave away for free. I have been so worried about him, I’m also worried about my safety meeting this person. It’s at a public location but still. I don’t have a lot of money actually. It’s a huge sacrifice. I hope I’m making the right choice. I have been traumatized myself being worried about him. The Bernedoodle came from a very reputable breeder and is so sweet. I feel upset and angry for being taken advantage of. I shouldn’t have given him away for free. What does everyone think? Pay the $500 and get him back? I also fear he won’t be the same dog as I don’t know what has happened to him there. It’s out of character for him to bite. His original owners were elderly people and he has been around kids and people of all ages. I think it’s the people and not him. I am very nervous. The have had him for 2 weeks.

Help, rescuing a Bernedoodle?
Post Opinion