Except Foxconn cannot make a watch like this for $1000, or even $10000. We currently do not have the infrastructure/tools to mass produce something like this yet. It's not just the parts, it's the assembly of hundreds of tiny parts to the highest precisions, the finishing details, the engraving.
Modern assembly lines simply can't pull off something like this. And this is why even the cheapest Chinese Tourbillion watches cost about $5k USD.
I think this is an excellent point, but I'll add that we don't have the economies of scale for it either. If there was enough demand for a tourbillon, an Apple-esque company would emerge (maybe Richemont or Patek) and drive the costs down for manufacturing.
Other than that, part of the appeal is the handcraftsmanship involved in these pieces. The engraving and setting work on my own Lange is a thing of beauty to look at under a magnifier, and it can't (yet) be achieved by a machine, even if the design and modeling can be done in software and the tools themselves can be mass manufactured.
Modern assembly lines simply can't pull off something like this. And this is why even the cheapest Chinese Tourbillion watches cost about $5k USD.