Brian, as with all collectibles condition is a factor. I think $15-$25 is very reasonable for run-of-the-mill Beckley Ralston putters. However, if you also have a Philco 90 in mint condition you want to include with the putter, the value is somewhat increased.
:i stumbled upon a putter with a stamp (beckley ralston) and i was wondering what it could be worth. shes in alright shape but i just wanted to find out some more information about this.