Since I can always buy an accurate timepiece for a few bucks, for me watches have to otherwise be FUN! That means bring a smile to my face!
I'm irrational as hell....
My first "good" rep was a Navitimer, quartz, bought 10 years ago. Still looks great, stopwatch works perfectly and has a neat dial. I don't remember what I paid for it. But a rose-gold gen Patek that my wife got me for my birthday some years ago is perfect, too. As is my auto Daytona rep, or 1973 Omega MegaQuartz that I'm wearing at the moment.
What I like about this board, and others, is seeing what gets watch guys excited, smiling. Some are really anal and are struck by the challenge of the 100% rep. Others like to wear something they couldn't otherwise afford.
I don't have any reasons or standards other than buying quality pieces and enjoying them until they get boring or a flaw bothers me. Then I give them to clients or sell them and am on the hunt for the next watch.
By the way, I've purchased gen 7750 chronos by Hamilton for under $500, excellent 70's mechanical Seiko chronos for under $100, a genuine mechanical Omega for $85 (on the bay), a 1920's Elgin for $50, and a real nice 1680 rep on the board for $125. If that isn't fun, I'm not a watch nut....