I think you spend at the level it remains fun. If you’re spending a lot to the point that you worry about it, you’ve gone too far.

I have a couple of nicer watches that I’ve acquired over (many) years. Every few months I’m likely to acquire something like a homage watch, which tends to be less than $100 but gives me something new to enjoy. Keeps the total cost down, and while I know they’re not the absolute best they work for me. I started with a Seiko 5 too!

NOPE

I think the other comments have established pretty clearly that they belong to your friend’s wife. One small thing from personal experience- are you sure they’re genuine? My FIL passed away, and there was a secret watch collection nobody knew about. Turned out a lot of them were replicas, although not all. It meant the financial consideration was pretty small compared to what we’d expected at first.