Wonderful service. I really like the idea. I think $10/month is way too low for the value you provide - think of the tax savings, and auditing capabilities you could provide. Good luck, I think you should charge more.
"As of now, we've now found you deductions that'll save you more than $3000 in taxes this year alone. To get more deduction information this year, please upgrade..."
It could be that I'm weird, but 10$ for me triggers some bias in my mind that makes me think the service is not legit, is fragile, won't realy do all it claims, etc. Strange.
(And I imagine that if you paid $10/month and it didn't find anything worthwhile, you could probably request a refund.)