I am sure you safely can buy a C3 subscription. A subscription means that there is a regular flow of cash to the company, which is a better guarantee for the future than a lifetime license like C2.
When I was using C2 which I also like very much, I taught about the lifetime license much often. I find the subscription system Scirra chose, very reliable. Even when I have no internet connection, I can use C3.
I hope at the end of this year to go back home to Botswana. When I am here in Europe, I am too busy and have too much work. However, at the end of the year, when everything goes according to plan, I will write my own adventure game which I dreamed of doing since my C2 license.
It is more important to be persistent in the goals you pursue than worrying about the tool you use to accomplish that goal. There is also a complete offline version of C3, which is installed as an exe on your local hard disk. You only need to login once a week. I am sure whatever happens, Scirra will make sure at least you can remain using that.
Last week I received an email from Scirra about the end of life for C2. Still, there are people using it and it is still on this laptop too. We can regret this but we have to move forward. C2 was nice but C3 is nicer.
Chris