If you don't get paid until Thursday you can do some things for free to help relieve the snake of at least SOME mites. When I noticed mites on my rescue boa (it was night and I couldn't go buy any Reptile Relief and it was going to take a while for my PAM to get to my house) I cleaned her tank with really hot water which got a lot of mites out, I also soaked her in water then ran over her body with a towel to get the mites off of her that were on the surface.

This of course, will not rid you of the mites in any way (You'll definitely need PAM for that, its worth every cent), but it will get rid of a bunch of the visible ones.