Hello. I have a 1.5 year old mini rex neutered male and I'm looking for some sort of fenced in enclosure for him to play in. He gets supervised free roam nearly all day when I'm home but since I've been going back to school lately I'm looking for some sort of pen he can have room to run in while I'm at school. He has a large dog crate as a cage and it measures 35in by 22in approximately. It is 24in tall. Are there any reccomended pens/fenced in areas to go around his cage that will give him room to run but so he can't jump over the side? I'm worried he will jump on top of his cage and then jump over the side of the fence or attempt to and injure himself. Any suggestions? I have a $75 budget preferably but if needed I will go higher.