IME, a built 1911 is worth whatever someone will pay for it.
Expect to lose about $1K on a gun that was custom built.
About $6-800 on a cookie cutter gun (Baer, Brown etc...).
"If you're not shootin', you should be loadin'. If you're not loadin', you should be movin', if you're not movin', someone's gonna cut your head off and put it on a stick." -Clint Smith