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I can tell you that we do not have any discount sales planned for the future. I still think at $79 though it still offers great value for money especially when you consider some alternatives cost more AND are yearly recurring fees!
The sale we did went on for around 6 months, I understand that some people would have forgotten to check later but the reason it was so cheap was for people willing to pay for a copy whilst taking on the risk of unstable/incomplete software. We don't think that the current state of Construct 2 reflects this risk any more so the normal price we think is now justified.