My recommendation: if you are developing this app, make it free. Unless there is an aspect that's hard to reproduce/innovative, someone else will build one and make it free; taking away any fame and fortune(from the fame) attached to your development. I'd be willing to pay for an app like this, but not if I can get it for free.
And the best price-point for any niche app(opposed to some major convenience app), like this is, is probably $.99. The problem is a lot of this info is available via the web, and people are cheap when it comes to small conveniences -- especially when there will be so many conveniences(apps) to choose from.