I think we have two different types of enthusiast. Some are happy to acquire the watches they really like over a period of years and keep them, eventually building a collection. Others, sometimes for financial reasons, don`t do that, they hop from one 'must have' to another and keep swapping. I belong firmly in the former camp, I`ve built a nice collection over a period of 20 years. I have a let a couple go that I wish I`d kept, but generally I'm happy with the deals I`ve done.
Golden rule is to always try a watch on before deciding to buy one. Not always possible with vintage stuff, but I always try to do this if I can.
3 watches I regret selling: A Rolex 116200 Datejust, a 36.2mm blue-dialled Steel Aqua Terra (tried to buy it back at a very strong price but the owner didn`t bite).......and a mid-70s Omega C-cased Constellation in steel with the correct bracelet. That's the one I regret selling most.
Financially, I should regret selling my 16610 Sub Date in 2014 for around 60% of its current value, but I don`t miss the watch at all. Sold it for more than I paid, which was OK......but selling at today's value would be more OK!