My opinion: If you really see your future as a game-developer, you should buy Construct 2 now.
If you want to become good at something you need Experience, but now you are limiting yourself with free version (Am I right?), 100 actions, 4 layers and etc...
It doesn't matter Construct 2 or 3, if you want to unlock your limits - unlock it now. You have to see the full potential of the tool.
In the long term, it will pay off.
Always invest in yourself - it is the best thing that you could do.
Worst scenario, you will need to save some money, to pay the update, but you already will have the tool to earn money, and hopefully you will know how.