What watch did you not pick up when the opportunity presented itself, and now you regret that you didn't get it? Maybe identical examples you find these days are now out of your price range, or whatever.
Mine would be this SMP 300 auto. Surely an 1120 movement inside, which I think was Omega's last version before they switched the 300M to coaxial. It was at a mall kiosk in California, mixed in with run-of-the-mill jewelry and a couple other watches (including a ladies' Constellation), with a price of $1700. I was told that it was recently serviced, but I didn't ask for proof or papers because I really couldn't buy it that day. I would've offered, and paid, $1500 if I were buying. Looking online now, I can't find this generation for much less than $2k.