Mobile Merchant Account

I tried to pay my medical school tuition (a five-figure sum) yesterday using my debit card. There were a number of technical problems during the process which might explain the resulting fiasco…
First, when the university official (i.e. "merchant") telephoned the bank for approval, the call got cut off just after I’d answered the security questions [...]

Hi
I am in 2 minds, the options for payment processing for my download products are:
http://paypal-ipn.com/
or
http://www.e-junkie.com/
?
i am confused why e-junkie charges by the month, and the other one above is a one of payment, maybe you get support and protection with ejunkie.
NOTE:
Merchant account is too expensive and costly paypal is cheaper & easier i have found, [...]