The Harry Winston Opus 11 watch. Around $230,000. I get that the miniaturization is part of the engineering accomplishment here, but I'd love to see this as a wall clock - harder to damage, easier to admire.
This reminds me of the 1906 Adams-Farwell 5-cylinder rotary engine that we featured last year.
51-second official video from Harry Winston:
2:20 video with the watchmaker demonstrating the watch:
More: Opus Eleven | Harry Winston
Tourbillon movement - GIF
1906 Adams-Farwell 5-cylinder rotary engine