Why aren't cars $5k then? Heck most basic motorcycles are $7k plus and they're well understood and very simple.
Cherry QQ (chevy spark copy) is ~$5K in china, being a ripoff removed R&D cost.
Great you literally cherry picked the lowest possible example for your argument. So after 100 years of development and ip theft yes the least featured model might be at that price level. I concede the argument. I look forward to getting my cheap robot in 100 years on the libertarian colony of vega
Cheapest "cars" in China start under $1K, Cherry QQ is actually decent in comparison. Want different example? How about micro controllers? https://www.youtube.com/watch?v=Rixo78hv_lw 3 cent in Asia, cheapest US based manufacturer offerings start at 30 cent.
You could in theory make 500K robots at 5K if you give up any notion of recouping development cost by tackling ridiculous margins, and instead concentrate on moving millions of units.