I recently sold a mint, blued, near new P-220 with box et all (that's important) for $650 in Wash state. As stated, location counts here.
What you have to realize is there's always alot of folks able/willing to buy $300 to $500 pistols but once you approach the $600 to $700 range that's a different group of people.
I might start out at $700 and work down from there. Good Luck, J. Parker