About 10 years ago I had the chance to but this Auguste Reymond, the chrono moon phase from the Jazz Age:
View attachment 22569
It was just under €2,500 at the time. It was and likely still is the smallest watch to house the ETA Valjoux 7751 movement with a case dimension of 37mm.
It was quite impressive and I ummed and ahhed that it wasn't a watch for someone in their mid-30's, now I am in my later 40's, I would get it straight away at that price. The watch is still in production, but it's going for over €4,000 now!