Because unless you know the amount of effort involved, you're talking out of your ass and giving him some
very bad advice.
There's a lot of potential to damage the suit when deconstructing it. Taking it off is a time consuming pain in the ass as you want to make sure you separate it carefully so the rubber doesn't tear. Then getting it off the TT takes care as well if you don't wanna get stuck replacing more parts from breakage. The leg is a pain in the ass to replace as the whole body needs to be taken apart to extract the broken leg stem, which any part of the body be broken easily if you don't know what the ____ you're doing.
Then the whole process is repeated as you disassemble the slim TT. And picking up a STT to cannibalize the leg is expensive as well assuming it's even compatible. Add that to the fact that he'll need to remove the lower knee of the Batman leg to swap it with the STT's for proper height and you're looking at accessing an Achilles heel of the TT, the knee joint. And if it's not compatible, that's more time and $$$ wasted.
Plus, if he tries to fix it and does more damage, she's no longer liable for it. If I were in his shoes, I'd take her to small claims and get her to buy a new one. She's responsible for replacing it since she broke it. He can print several ebay completed auctions as proof of the current price and in the end, he's only out the $50 filing charge which he can also get back if he includes that in the suit.
Get a clue before posting.