Best places I find to score.

I have picked up quite a few razors for under $5.00. That's the fun of it for me, getting a razor for as cheap as I can. Well, cheap but still fairly nice, not a piece of junk.
My best scores have come from small town antique stores selling lamps, furniture, place settings, silverware, etc. A lot of these have a small case near the register that has a few magazines, LPs, pens, and other small items. I find a razor now and again. I like these places that don't really sell what I'm looking for. It's like they have a few odds and ends in a case that's just there. They really don't know much about these things and almost just want to get rid of them. Their focus in on the other antiques. Furniture and the big stuff.
Just my hunting guide.

Another place I have found is ask your local barber. Apparently some people don't know what to do with the old razors so they take them to their barber. One barber I know just tosses them into a box under the counter.

And, of course, lots of contact with family and friends. Get the word out about your hobby and they will start turning up there as well. I have family looking in four different states! haha!

Good tips. There's a collector sale coming up in town this weekend.
Even though some guys won't have razors, I ask them anyay.
Sometimes they have them, but don't put them out or bring them to the show.

Bring a pad of sticky notes and give them your phone number.
Why not? every bit helps!

Very true, Maxman. You gotta ask them. I don't know how many times I went to a show or booth and asked the booth owner if they had any old safety razors and they usually say, "I know I have some back at the house/warehouse/etc.. but I didn't bring them with me"

I hunt flea markets junk stores antique stores and garage and estate sales.

I got most of mine this past year off of E-bay.