If I remember correctly, in vbulletin you could specify various different amounts to pay for any one subscription type so by making the length of each payment the same (e.g. 1 year). ie a member can choose what they pay depending on what they can afford.
Is this possible, or would I just create lots of 1 year upgrades, one for each price?
Or, ideally it would be nice if the member had an empty field and could just add their own amount, like a donation.