Actually the pricing structure was one of the reasons I have never purchased it. If I buy it it will be Master only. Any other pricing is too much. Hearing that they could be getting more expensive is concerning.
While I don't feel that GMS is as intuitive as C2; GMS assigned Event system directly to objects. Which let's objects behave more OOP. Which is far better than open events :(
Also the effort that YoYo games makes to for true cross platform compilation should never be underestimated. With that you can create native language support. Allowing new technologies to be directly incorported rather than having to listen to "waiting for technologies to catchup nonsense."
Take this as an example. GMS developers could incorporate a UDP network later years ago. Where as C2 needs to wait for browser developers to provide access layer. Same with WebSockets, WebGL... so on and the list goes on. Browsers are and will always be playing 4 year catchup on a technoligical level. C2 needs browser based wrapper designed to work in any other environment.
However, GMS pricing is heavy handed. Other tools similar have yearly licensing. Which can end up costing even more than GMS.
C2 license is easily a very generous and fantastic license. But at the same time C2 just isn't as mature distribution. :( great product though :)