When does Vintage status start increasing price

Last year I bought a 1971 Yacht Club in gold, condition not great. When I shared it on this forum (before restoration) told that the yacht club was one of the last in house mechanical watches made before quartz, that the self wind mechanism was brilliant, but unfortunately the price paid for same had dropped and they weren't worth what they used to be worth, and it being 18ct gold didn't add much to that value.

Regardless, I sent the watch to Switzerland and had a complete service, all worn bits replaced, new face and hands too, even the scratches in the gold were filled with gold by laser and polished out. Keeps great time and looks great. I added an aftermarket strap in blue polished sting ray which I feel looks great too.

Now I once traded an old rusted Rolex Submariner I had for an inexpensive omega. The company then rebuilt that old Rolex and then sold it as a vintage Rolex for more than the new larger Submariners were selling for. How is that?

So now my question. Should I just wear my IWC as an everyday watch because I like it and it will never appreciate more than inflation, or put it in the drawer as like new in the hopes that in another 10 years my vintage 1971 IWC Yacht Club in 18ct. gold will be a collectors item and worth a lot more in its as new state?

I am not a vintage market expert - but I do not think you can approach pricing of vintage watches as a linear, time-constant factor that starts at a specific age of any watch.

Not every IWC, at 40 years of age will be worth a specific factor of its original retail purchase price. There is great diversity in each line of watches and specific references may be special based on movement, dial, case, or other limiting factors - which at some point in time fall into great demand/favor that highlight its rarity.

Some references are rarer than others - and some designs are not as timeless. Many watches from the 60s and 70s look like they're from the 60s and 70s and do not have a "timeless appeal" that contemporary buyers may be looking for.

There are other factors too - such as currency and precious metal prices that can affect vintage prices to some degree.

That said - do not write off your Yacht Club. That watch has come into more recent appreciation and I believe its value will outpace inflation by a wider margin...