It's going to be strange, that's for sure. Patek, VC, and AP will never lower their prices, but their production numbers are still relatively low. Same with ALS. Within that category you have outliers like Richard Mille (with lots of watches available but all at prices no one would bother paying for for a used watch) and Roger Dubuis (which heavily devalues if it's not from the time when he was head of the company in the 90s to early 2000s).
Under this you have Rolex (stainless steel is the only holder of value, everything else devalues), Omega (Speedy only, everything else devalues), and the rest (which all devalue regardless). Under that you have Oris, Longines, and the rest which guarantee to devalue.
There are strange ones in the middle like Tudor, which have managed to find a way to be attractive to the up-and-coming wealthy, but the designs are of-the-moment and will age obviously (but not necessarily badly). Some Tudors hold, but most devalue since it's still a poor-man's Rolex.
Grand Seiko doesn't seem to care, nor does the market. They don't devalue that heavily, but they don't increase either.
It's the really in-depth collecting parameters that are in danger here. A correct dot-over-90 bezel used to be able to increase the price of a Speedy by 5-10K if the condition was good...but if no one cares (or if someone simply takes it into Omega servicing knowing that everything damaged will be replaced), then that value won't work on the open market.
Actually, I don't know why more people don't do this: buy the lowest price you can afford, take it into servicing, and still have a brand new watch for a fraction of what a brand-new watch would cost.
Hold on....the Breitling Cosmonaute wasn't automatic wind at the time it was used in space. I used the movement pic here: >>15865066
It's an awesome watch though...one day I might pull the trigger.