I asked a question close to that earlier (before I actually bit down and purchased a plan) and the answer I received was that you wont get the promo discount with a PayPal payment.
You can however use a Debit card if it has the VISA or MASTERCARD symbol on it and get the discount. At least, that's how I did it (I of course e-mailed support and asked beforehand) and I received the discount.
Hope that helps.
[color=#CC0000]NIHALFOFF[/color]! $25.00 off a monthly plan or $48.50 off a yearly plan.