Deer mice can be difficult to find.
They are not as prolific, so I raise just a few. I find that hatchlings refusing regular pinks after the usual tricks (live, f/t, brained, cut in half, cup feeding, etc) will often take a regular pinkie that has been buried in dirty shavings from the deer mice for about 15 minutes! So you don't need the actual deer mice pinks themselves (usually). I have been thinking of selling the dirty shavings, lol! (talk about recycling!)
Groups of friends or herp society members in a partiuclar locality could get together and just one of them keep a small deer mouse colony for this reason. BTW, you could also try pinks or bedding scenting from hamsters, gerbils, rats, or any other rodent for variety to see what works.