One common reason people use to not buy a multihull is because they say "they cost too much in a marina" or "there's nowhere to moor it"

Over the last 35 years I have sailed multihulls in over 40 countries and I have never had a problem finding somewhere to moor. So a five word answer is "it is not a problem".

Mind you, that has only been with boats up to 38ft long and 23ft beam. I know that travelhoists that can lift boats over 24ft are few and far between. Certainly if you plan to buy (or build) a big multihull you should  investigate where you will lift your boat out (or in !) before committing yourself.

Having said that, there are multihull friendly boatyards, obviously the Multihull Centre is one, another is Jaynes Marine in the US, both can lift any size multihull.

When you have a multihull you have a different mind set. No one likes rolling at anchor, but multihulls don't roll. They can be beached or dry out at low tide. Monohulls, by and large cannot. So there much less need to visit marinas than there is if you have a monohull.

If you do find a marina that looks too small see if there is an "end tie" you can use or maybe an area that is too shallow for monohulls.

My home port of Millbrook is home to maybe 100 multihulls, but only five monohulls. The reason is that the creek dries out completely at low water

When cruising I usually phone or call a marina on the VHF the day before. If they ask for extra money, which occasionally they do, I say I'll go elsewhere and they always relent. As multihulls have become more popular marinas no longer turn them away, they cannot afford to.

We left our Skoota 28 powercat in a US marina for the 2013/14 winter. when i phoned them they first said "We're full, sorry" then they said "How long are you" "28ft" I said. "Oh, we have lots of space for small boats, it's berths for over 35ft boats that we don't have". So it's length that is often a problem, not width