As already advised, your net income would need to be over $155,000 for the Awesomium licence to be applicable to you in the scenario you're describing. In fact, even if they specify turnover BEFORE taxes, I'm not going to be too concerned with these charges. They are more than reasonable.
Also, $2900 is not so much, despite your aggrieved tone, and neither is the Scirra licence. These values are pitched against scale. I also think of them as relative to what they're allowing you to do.
The Construct licence is providing you with a toolset and an engine. The convenience and utility provided in instances where a game draws in a large revenue stream is most certainly worth the minuscule amounts (relatively) that are required in these circumstances.
The same again applies to Awesomium. It's opening up a whole distribution channel that would have been unavailable to you otherwise.
If you don't think this is worth the money, learn to code the underlying technology yourself and it won't be something you have to worry about. Your concerns about relative value are a little bit shocking to me, draconian taxes notwithstanding. Makes me think of a certain apocryphal Picasso anecdote .
EDIT: Haha, ignore my faulty math up top. You'd have to make even more than that if it's calculated after taxes (i.e. if it's based on net income).