Chargify can charge what it wants, but the pricing change was abrupt and BIG. Apps on the ground floor went from FREE to $1200/year. No grandfathering, 30 days to accept. For a service that needs to be integrated, that's a terrible move that shows no respect for startups.
What's worse is that if you're already using them, you basically have no choice in the matter since the alternative is trying to get all of your customers to sign up again, which is basically a non-starter. Note that they also doubled prices for their first tier of paid customers from $600 to $1200.
This is the evil next business model: Free "bait and switch". Get businesses to sign up with a service that is free but requires integration. Then start charging. Integration makes it very difficult to switch.
Well, technically you have all the customer data in your gateway's info manager (like Authorize.net's CIM), but it would still be a real bitch to take that and do anything useful with it. Plus, the clock is ticking on your 30 days to get it migrated to your new setup.
Honestly, I haven't looked closely at the raw A.net API. I heard about Chargify, pricing looked good, and it fit my model. Basically, I wanted someone else to deal with dunning, expired cards, running the periodic charges, etc, etc.
