Gravity Perks: PayPal One-time Fee 2.0.beta1.1

Add a one-time fee to the first payment of a PayPal Standard subscription.

What does it do?
The One-time Fee perk allows you to add a one-time fee to the first payment of a PayPal Standard subscription. For example, let’s say you’re signing users up for a web hosting package but need to charge them a setup fee on the initial payment. That is now possible with the One-time Fee perk!
How does it work?
PayPal Standard does not support a one-time fee on subscriptions natively; however, it does support a trial period. This perk uses the trial period functionality to simulate a one-time fee concept for PayPal Standard subscriptions.
Unfortunately, this means if you need a trial period and a one-time fee, this perk will not provide that functionality for you. Once you’ve activated the one-time fee, the trial period options will be disabled on the PayPal feed.
There are some interesting combinations that can happen with the One-time Fee and Recurring Amount options. Here is a list of these combinations and how they are processed.

If the One-time Fee and the Recurring Amount options are both set to product fields, the totals will be added together for the first payment and the total of the Recurring Amount field will be used for the subscription amount.
First Payment = Recurring Amount (RA) + One-time Fee (OTF)
Subscription = RA
If the One-time Fee option is set to “Form Total” and the Recurring Amount option is set to a product field, the form total will be set as the first payment and the Recurring Amount field will be used for the subscription amount.
First Payment = Form Total
Subscription = RA
If the One-time Fee option is set to a product field and the Recurring Amount option is set to “Form Total”, the form total will be use as the first payment and the subscription amount will be set as the form total minus the total of the One-time Fee product field amount.
First Payment = Form Total
Subscription = Form Total – OTF