We have pet mice. They are fun for my daughter who is 12, but there are a few things I wish I had known up front.
First, I wish I had know how common it was for female mice to be pregnant when you get them from a pet store. Needless to day about 3 weeks after our purchase we had 5 more mice which we kept. All these mice meant that my daughter had 4 tanks to clean. One of them was a 20 gallon tank that all 5 girls lived it. Thankfully she was excellent at sexing the babies, and we had no further litters.
I also wish I had know how common mycoplasmia is in rats and mice. 3 out of our 5 girls got it and died within the first year. Tumors are another issue that we dealt with in one of our girl mice.
I guess what I am saying is that it is important to know up front what you are getting into.
If we were to do it all again, I think we would just get one boy mouse. Boy mice can't live together like rats can.
Best wishes with you decision.