At this point, short of the unrealistic ("$500 WW2 1911s, crate of 10") I'm pretty much set.
My last two were getting a Broomhandle (found a 30s commercial Bolo shooter that still had a bore left) and the Vector 89K I couldn't afford when I was ill for the year or so it was available commercially. The Vector really doesn't count much as a pistol, but it's one until the SBR stamp comes back any day now.
I'm at an obscene level in my collecting though, there's nothing left to do but shoot the few dozen I've got, not that there's anything wrong with it.
With enough effort, you can probably get anything you want with enough time and searching - the net's made it a lot easier than when I started buying them.