Matt Jansen charges like $400 per month for "coaching" and has been known to only communicate with his client once per month. Again we should be smart enough to know when we are being hustled
$400 is about the going rate for prep coach's in the lower ranks (non-pros) but if you're not communicating with your clients (at any level) at least 2-4x's per week with 1-2 of those days on a face to face via Skype, FaceTime, WhatsApp, etc any amount of money is too much. If he's only communicating with his clients once per month, that client is getting taken for a ride.
There's more to being a coach than just writing programs and making adjustments...that's not coaching.