Acea Clubb

I have an 07 f150 with 150k on it, at first I was told my motor needed replaced (bad news) but after looking further into it I'm now pretty sure that it's a cam phaser problem, I've noticed there's alot of talk goin on about them and was wondering if anybody that's gotten them replaced knows a ballpark estimate of how much it's gonna cost to get the job done, thanks y'all