I've never actually bought PAM to treat mites so I'm not really sure if this is a bargain or what lol but LLL Reptiles has it for sale and Pro Products does also (They are actually having a sale on it too ) I'll post the links to them both for you.

http://lllreptile.com/store/catalog/...rovent-a-mite/

http://pro-products.com/provent-a-mite/

I usually use Reptile Relief mite spray since you can use it on the cage and spray it directly onto your snake. I would post a link to it but if you type in Reptile Relief into google search it will give you a ton of different prices for it

Also, it won't hurt to treat the new snake coming in its better to be safe than sorry!

Hope all this helps.