Well, I was actually thinking about the same strategy as you......offering him an amount he could/should not refuse.
but then shortly after, I came across a beautiful Painted Desert MC2 in L size. The XL fits me better but even finding an Attitude in L or XL is difficult enough so I was happy, especially since it was almost unused.
Anyway, I forgot the Sunburst for a while but was later considering to offer him 4000$ for the frame (What was your magic number?) but then other things happened in my life and I had to focus my monetary capabilities elsewhere for a while.
....and now the opportunity is gone and you have the frame. Well, I guess it's only fair. I have a beautiful bike now and should be happy with that and appreciate the fact that someone else also found the bike of their dreams.
_________________1991 Gary Fisher, Hoo Koo E Koo
1992 Klein Attitude, Sunburst
1994 Klein Fervor, Nebula Green1995 Klein Attitude, Painted Desert