For me the pricing model is perfect for something like this. $2.99? thats right in my 'don't even think about it' impulse range. $5.99 for additional features? I'm already paying $2.99, its not much more AND I get more stuff. Bravo!
I'd rather make people happy they found a good bargain and reward them for being early adopters than try and milk out every last cent out of this. So it's cheap on purpose for now, but I'll probably raise the price in one week or so.
From my personal e-book experience going from $.99 to $9.99 cut down sales by about 90% (so it was the same amount of revenue, but higher processing fees), and going to $49.99 only decreased sales by a further 33%-so $49.99 was massively more profitable! This was over thousands of e-books by the way, not any particular one.
<Insert standard "this may not apply to everyone but is an interesting datapoint" caveat here>