I go down to an old antique shop locally, and the owner gives me great deals on his old pocket knives, especially the old, broken, worn out ones. He's glad to move them on out; I clean them up a little, get them to where they're nice to look at. Most of what I've found are in such bad shape they have no collector value anyway.
Inheriting my grandfather's old (1940's) Robeson Stockman got me started. Inspired me to start studying what all the different patterns are, where they came from, manufacturer histories, etc. Very interesting stuff.
thx - cpr