I wouldn't go with cypress mulch. We used that with our first BP and every single bag had bugs in it, no matter where we got it from. I think you should go with Aspen, it's cheaper, lasts longer, holds humidity, and it's hypoallergenic (not sure if that'd matter for you). You can get a bag of Aspen at WalMart for 2.97 a bag. Plus with Aspen you can see the little trails your snake leaves when it moves around in it's cage