Brass from shooters is getting hard to find since most of the folks are getting into reloading. I had the same problem with 340 Weatherby brass. If you Gioogle 264 Winchester you will find quite a few places that sell it and you can decide if it is in your price range.
Critter, Most places are on backorder for new 264 brass, I have a couple thousand rounds loaded but our prairie dog season is close so it won't last long. anyway I'm still looking for GOOD used brass if anyone has some they want to sell.
I cleaned out my local Sportsmans Warehouse when it was shutting down. But now that I think about it, I remember there being some at the Loveland store last week. If you're still looking, I can hook you up, assuming it's still there. PM me if you need it.
From the books that I have read, there is a lot of importance in knowing every nook and cranny of your hunting territory as well as the animal that you are hunting. So scouting as much as possible, just walking the land, will give you a good idea of what's around the corner or what's on the other side of a hill. Which can be very beneficial.
Making your own maps of human and deer trails, and different types of foliage such as group of pines,...