Figured I’d check back to see if anything changed in regards to you using Amazon billing. I prefer your service over the amazon cloud9 and would like to upgrade to the paid service. Amazon grants me developer credits each month and I’d love to be able to use those. I wrote back in Sept 2017 and asked the same question.
c9.io and AWS Cloud9 use completely separate billing systems, so you won’t be able to use AWS credits to pay for a c9.io account. Is there anything in particular you don’t like about AWS Cloud9? AWS Cloud9 is the newer version of Cloud9, and c9.io is eventually going to lose support, so you’ll likely have to transition anyway, it’s just a matter of time.
Amazons version does not support https and trying to connect to a running instance from the net is a pain in the back side. If they could make it work like yours I’d jump right on it.