You're all lucky if you have at least one in your city...
Here, in Montreal (Canada), we used to have 1 gallery specialised in photography...
(For those who don't know Montreal, it's 1 million people big...)
The gallery closed down because they were not able to sell any prints.
They tried selling Lomo LC-A's on the side to cover cost... and sold none (people were saying: "Duh... it's not even digital")
They moved to a small side street, were opened on appointment only...
Last that I heard from them, they closed down for good...
But on the good side, the city has plenty of free exhibition spaces opened to any artform.
I think Britain still has the upper hand compared to my province when it comes down to photography.