I have set up a subscription form for an e-journal that contains a drop-down list with 3 predefined subscription options. Each option is linked individually to Paypal.
Also on my form I have a section that asks subscribers if they are interested in buying any Back Issues of the e-journal. This section consists of two Text fields - one to enter the Back Issue number(s) and another field for filling in the amount for the selected number of Back Issues. Is it possible to pass the Text field containing the amount to Paypal as a Purchase Field. I am not offered it by default.