One Time Sign-Up Fee HALP!

[cheezcake]

Hello, would it be possible for a PayPal Pro form to have a checkbox, the state of which would determine if an extra sign-up fee would be added to the membership signup?

If not, is it possible to add a trial amount which is greater than the regular subscription amount to a paypal pro subscription form? (Specifically, the trial amount would be the regular subscription fee + the first time signup fee)

HALP GUYZ, YOU'RE MY ONLY HOPE!