Ok I'll put it out there:)
We're running a range depending on keyword that is between $2 and $10 CPT bid.
It's very hard to compare with other apps and say this is/isn't similar to what others should bid as our app is in a non-gaming niche so we don't expect a huge volume of impressions/clicks.
Not seeing any significant difference at this early stage between the $2 keyword and the $10 which while it should be as popular a search term as the first has yet to see any impressions.
All told I suspect Apple are trickle feeding things to make sure everything is working - devs are spending real money after all - and once they are happy will turn the faucet on full. At least I hope so!
*I've yet to even see an ad any ad on my iPad, and very very few on iPhone.