I've decided to keep to one standard price for my events, in the interests of simplicity, from now on - I'm a bear of little brain, at least when it comes to office work. I used to charge more for paypal and for entries on-the-line too. There are relatively few postal entries now anyway, (but if you want to do it that way why not? - I'm one of them when I can be bothered, still using up spare SAEs from way back). Also many ACME riders get their brevets returned by hand, usually down the pub on a Wednesday evening. It could all get very complicated.
I still request permanent entries by post - I suspect if I went online with them I'd be getting last-minute rushed requests for a brevet. But most folk I know prefer DIYs by GPS now - it makes a lot of sense to have routes start from your front door, which is one of the reasons why I got into organising perms and calendar events - quite selfish of me I guess ...