What gun do you most regret not purchasing?

For me, it was a John Wilkes 16 ga SL. I let my friends and wife talk me out of purchasing the gun. My friends thought I should be able to get a sleeved gun really cheap and my wife could not figure out why I went to these folks for advise and then did not want to follow it. It would have been my 1st English SxS and it was the 1st gun I came across that I really liked. At the time I figured there are lots of guns out there. It haunts me still.