Are There Any Other Fees Besides The Subscription Fee?

The only other fee that applies is a processing fee for PayPal. All royalties for client galleries are paid to you minus the PayPal transaction fee. 

The processing rate for PayPal is a low flat rate of 2.9% + $0.30 per transaction on the gross order total for all credit card types.

Example : If you were to set your 8x10 royalty pricing to $10, the total amount charged to your client would be $12.35 ($10 royalty + $2.35 base print cost). The transaction fee taken from the gross total of $12.35 would result in a 66¢ PayPal transaction fee.

$12.35 x 2.9% + .30¢ = .66¢