After you've got a better handle on your market, have traction, and have passionate paying customers singing your praises, switch to a subscription billing provider and grandfather in the old users at free for life.
This assumes that you have nearly zero marginal cost per account, or a growth curve which can absorb the early adopters as a cost of doing business.
Otherwise, this seems like a good strategy for testing the waters with a new product.
Anecdotal, I know.
The entire online industry and everyone who takes credit has to hand over %3 to credit card processors, who take money from both sides of the transaction.
It just sucks, that's all I'm saying. I wish there was a better way...
Every merchant I visit is giving me 2% off with Visa and a bank in the middle to make sure of it.
Braintree claims that their pricing is very competitive. I don't doubt that it is, but being in business with them for a single year costs a minimum of $1659* (supposing you need recurring billing). That's a lot for someone who wants to get started charging for a small web app.
I've been really discouraged to get started because I know that as soon as I do I'll be paying high monthly fees that I'm not sure I'll be able to cover.
Thoughts?
*http://www.braintreepaymentsolutions.com/pricing