I have no idea why a car should be more than 10k. On Amazon you can get a go-kart for less than 100: https://www.amazon.com/s?k=go-kart
It is really the same comparison. A true every-day wheelchair or a "hospital" wheelchair that will make you sweat after 10 yards
A set of wheels and a cushion do not make a good wheelchair, if you want to live an active life. Please see https://news.ycombinator.com/item?id=41721976
I am from Europe and chairs are a bit less expensive here, but an "active" wheelchair is usually more than 2k$ anyway, often closer to 3k$. And some are much more than that (for instance if you want a soldered chassis)