At these rates, it looks like the minimum cost per year per zone is $18 ($1.50/month, $1.00 for the zone and $.50 for the first million queries). This is extremely competitive for folks who only need to manage a very small number of zones. For those with many zones, one of the existing services from UltraDNS or VeriSign would be more appropriate.
Not sure how many dns lookups get done a day but I see about 6 - 7 million people daily.
20m lookups per month for $14/year, and they don't actually track or bill the excess stuff, I've asked them about it before and it's not implemented with no ETA.
Been with them for a long time and love them although their interface is ugly.
$0.25 per million queries – over 1 Billion queries / month
bleh.