A manual wheelchair is less complex than a bicycle, and I can get a decent bicycle for a few hundred bucks. The fact that basic wheelchairs are crazy expensive has little to do with the chairs and a lot to do with insane bureaucracy.
And also economy of scale, there are 1 billion bikes in the world VS 65 million wheelchairs.
If you look on ebay there are loads of wheelchairs for sale from about $100-$200 (£80-150 if british). They are mostly made in China and I think work ok - I bought one for £80 to use with my dad and it was fine. But that was for occasional use. I guess if you were to use it all the time you might want something fancier.
Economies of scale and lack of competition.
When you have all the components for a cheap bike made in 100s of thousands by ie Shimano, the price goes down dramatically. Wheelchairs? Unless there is 1 dominant manufacturer its not going to happen to smaller shops, and monopoly has its own issues.
When you have regulatory tape which require some steep price hikes to cover some specific aspect (which may not be that important), combined with above you get what you get.
I was recently wheelchair-bound for a month due to my recent paragliding accident (crutches now for at least 1 month more, overall an interesting experience of various limits lying everywhere you don't even realize until you are there), and can appreciate even basic wheelchair and its various functionalities. Its simpler than bike for sure, but its also foldable (at least mine) and relatively easy to pack into trunk of any decent car in a minute (not for me of course but accompanying person).
You cannot get a custom designed bicycle for your body for a few hundred bucks, particularly from a US manufacturer
Third party payment markets tend to have prices spin out of control. Usually the end user demand is fairly inelastic, and the third party is not driven by cost efficiencies in the negotiation. Getting into those markets as a new supplier is very hard as typically a select few incumbents have longstanding relations/deals with the third party.
I don’t think most bicycles are designed for 16 hours of daily use…
Yeah, but can you climb chairs with a bicycle? There are wheelchairs that can do that.
Well, bicycles have more demand and volume (presumably), so that would play in to it. But yes, bicycles are a good point of reference.
You probably don’t want to sit on that cheap bicycle for 16 hours a day. Almost guaranteed it won’t fit property and at best will give you saddle, sores and worse cause back knee issues.