Cost/ conversion is a relative metric. That number is made by dividing the costs by the number of conversions you have, so the larger the number of conversions, the smaller your CPA will be. It's relative depending on how you're looking at the account. For individual keywords it may be larger, since it's a small number divided by the cost, but on the campaign level it could be smaller because it's the total number of conversions divided by the cost. Make sense?