I would venture a guess that the most expensive places in the states would be either Ft. Lauderdale on Florida's Gold Coast or San Diego/Los Angles in California. Lake Michigan around Chicago might be an eye opener as well.
How 'bout it Limeydal, what's the going rate in San Diego?
Speaking of Florida, the land of fun in the sun, where are the members of this forum from that area? It is surprising to me that I never see a post from that area.
Down here it's pretty reasonable. I trailer but as I recall my buddy Captain Pete pays around $300 a month for his 26 ft. Delta. I think though that the yard must charge around $300 an hour for labor based on a couple of repair bills I've had down there.
We have a lot of Federally protected waters here and increasingly they are installing moorings for transient vessels and charge per night. Where they have these, anchoring is prohibited to preserve the sea floor. The rules however on mooring on a permanent basis are lose to non-existant, in non protected water. I was reading about Hawaii a while back and they have very strict rules on laying at anchor there, very strict!
The costs in UK, between berthing and fuel are truly scary. You have my sympathy!