Do you want a nationwide survey or just a general idea of what you may be up against in the future?
Someone (well, it's me, now) will probably suggest that the average hangar is about £0.25 for plastic, which is good inside or out but has very little in the way of perks. Wooden ones are better but have maintenance issues outside....
Pedantry over.
I've paid £100 p.m. for a share in a hangar without doors on a farm strip and no facilities but the pleasure of being there with Good People and the chance to help with the livestock...
Currently I'm paying £130 for hangarage to include clubhouse facilities (kitchen, heat, telephone...) and at the hangar, hosepipe and electricity.
In places such as these, landing fees are included.
The SE is crowded, waiting lists are common at popular airfields and hangarage is generally more expensive than elsewhere. Generalisation over.
I hope that helps a little.
Edited to remove typo - and note Aerbabe got in first....