I personally HATE the stock options paypal has for subscriptions and invoices ... I used it for more than a year, and it was a disaster!!
If you want a system that is cost efficient, professional, and integrates beautifully with
Paypal (as well as 2CO, authorize.net, and most standard payment processors), then check out
FRESHBOOKS
I have been using them now for about 10 months, and I love it -- my clients have nothing but good feedback too!
(your first 3 clients are FREE -- to let you try the system)
