My .02 cents, watches aren't where I'd park my money for a return. Buy a watch because you like it. I have an Rolex Sea Dweller I bought almost 30 years ago. I think I paid $3000 for it and it's now worth somewhere around $10-12K from what I can see on line. Except those are sellers prices from an AD or used watch specialist, I don't know if I'd get that much privately. Then there is the sentimental value, I'll never sell this thing but leave it to one of my kids. Regarding the Deep Sea Dweller, I'm not sure that's the Rolex I'd invest in for long term return. It's an interesting watch but IMHO doesn't really fit the product line so might not appreciate in value as much. I'd go Daytona or Sub if I was hoping for a return. If you want a Deep Sea Dweller because you want one then by all means that's what you should get.
You may find this interesting if you're looking for investment/collecting time pieces.
https://www.bobswatches.com/auctions