But you're still up against freely available libraries that let a web developer build similar functionality, as as jquery.payment from the folks at Stripe:

https://github.com/stripe/jquery.payment

While it's not a completely like-for-like comparison, I suspect it will be tough to justify $299 per single web site for many businesses that might use these tools in the first place. Personally, I'd want solid data about conversion rates to back up the marketing on the creditcard.js website before I'd consider spending real money on anything like this.