Petsmart carries ArticMice frozen now. You can buy just a few but.. it's expensive.
To get a good price, you have to buy a lot of frozen mice. But, they keep really well in your freezer, no trips out to get more every week.
Feeding frozen/thawed or live is a personal choice. Some people are rabidly against feeding live. I feed live to mine, because I breed my own rats. Just easier for me. Until I have an overabundance of rats, I plan on just feeding live myself. Never ever leave a live mouse or rat in the pen with your snake for very long unsupervised.
My Hepburn was treated for parasites, but the vets never said that she got them from the mice/rats.
Wolfy