In addition to the revenue share that Bandcamp collects, payment processor fees apply to all transactions processed on your account. Here's how it works for physical sales:
For Enhanced Payments accounts, payment processor fees for physical merchandise are identical to those described here for digital sales. For accounts using Standard Payments, sales of physical merchandise (which are paid directly to your PayPal account, with some exceptions), PayPal’s standard transaction fee is 3.49% + $0.49 USD. There are two ways you can lower that fee:
PayPal offers a micropayments rate of 4.99% + $0.09 per transaction, which ends up being a better deal if most of your physical merchandise transactions are $12 USD or less. You can sign up for micropayments at any time. There’s nothing to do on Bandcamp; just contact PayPal Micro Pricing Support at 888-433-6829. You can switch back to the standard rate at any time by contacting PayPal.
Also, be aware that PayPal allows you to use only one rate at a time. After you switch a PayPal account to micropayments, all items sold via that account (through Bandcamp or elsewhere) will use the new rate. If you happen to sell a lot of items priced more than $12 USD, you’ll notice the micropayments fee will be a bit higher than the standard fee.
Apply for merchant rate pricing. Depending on your monthly volume, PayPal’s rate can be as low as 1.9% + $0.30 USD.