AITA for buying my son the more expensive wheelchair?

"I make good money but I can’t stand extravagance. I’m a firm believer in teaching my children the value of a dollar and saving for the future.<br><br>I have a 13 year old daughter and a 6 year old son. My son is severely disabled and requires special care and equipment. He loves video games and is very talented at them, and my daughter loves to travel.<br><br>Last year, my son asked for a very expensive wheelchair that looks like a spider, and is hugely popular among kids his age. I thought it was a joke, and was appalled by the price. I ended up getting him a more reasonably priced one, a power wheelchair he could operate with his joystick.<br><br>My daughter has traveled with me to four different countries, and has visited most states in the US. I take her to expensive restaurants and buy her designer clothes because she likes that sort of thing.<br><br>My son spends most of his time playing video games and watching YouTube, and I give him a very generous allowance to spend on nerdy things he likes, within limits. He wanted a very expensive gaming chair that was shaped like a dragon, and I reminded him that he can’t sit in chairs because of his disability, and bought him a more reasonably priced gaming set.<br><br>My ex-wife/son's mother (we're divorced) recently visited, and she made a big issue out of the fact that my son’s wheelchair, his gaming set, and his adaptive car seat weren’t the most expensive options available.<br><br>This has been a recurring issue, and it’s come to a head because my son is now asking for a very expensive (about $20,000) wheelchair that is shaped like a dragon and made by a very small company. He would basically be the only kid in the country with this wheelchair. The reviews I’ve read make it sound like a great wheelchair, but I still can’t stomach the price.<br><br>I told him that he can have any wheelchair made by the big companies (he’s decided he wants to stick with the power wheelchair style), within a certain spending limit, but I’m not spending what amounts to a car on this wheelchair. He understands, but is making it very clear that he would still like the dragon wheelchair.<br><br>AITA here?"<br><br>Edit: I feel the need to clarify a few things. When he buys something, I let him choose to spend within a budget. I don’t pick out his clothes, toys, or game controllers. He goes to the store and chooses what he likes, as long as it stays within budget. What I’ve learned in the last few hours is that I should probably let him choose between open-ended options, within a budget, rather than giving him a yes or no option. “Do you want a dragon wheelchair? No, you can’t have that one.” Should be “Would you rather have this company's wheelchair in blue, green, or red?” I’ve also never, in my life, made my son wait to do something I was doing with my daughter. If she was going to the movies, and he wanted to, he came too. The only time he doesn’t come is when he isn’t invited, such as school dances or girls’ nights, or when it isn’t safe/accessable for him.<br><br>Edit 2: I think I need to clarify even more. When I say within a budget, I don’t mean that he pays for everything. He doesn’t save up and buy his own clothes, I buy them for him, I just let him choose which pair of shoes he likes, or which game controller he likes, or which nerf gun he likes. I let him decide what to spend my money on, and encourage him to prioritize and think about his purchasing decisions.