for the moment, I would consider the concept and not so much the price. What they charge is likely not a lower bound on their internal cost structure. The product came out of beta today, so their pricing seeks to first attract those users with a high need and to test their pricing capacity. Better to try to charge too much and then go lower than to take too little.

Given that their engineering expenses are a fixed cost and the majority of their spending, they'll be able to lower prices as they scale.