Should I get another leopard gecko? There's one with a dropped tail I want to help?

I've had my leopard gecko Sgt. Pepper for a year or two, I got him when he was 1. He's in a 20 gallon long tank, and I have an extra 15 or 20 gallon (I'm not exactly sure) I could set up almost completely with just spare reptile stuff I have. I'm only missing a heat pad but I have an extra heat light. Anyways, there is someone selling a female leopard gecko because her tail dropped and they can't breed her this year, so they don't want her. Mine is a male and I don't want to breed them, but I do want to help this gecko. She's asking $30 for her or she wants to trade for a couple of those Exo-Terra hides, and I have a spare extra large one she would trade me for her. I have my leopard gecko and a crested gecko for reptiles right now, should I get this female one?