ultimately it's up to the landlord. However, when i lived in a key meter flat, we had it changed to an ordinary meter, then had it changed back before we moved out
It's up to the landlord (although my tenant changed the meter without my permission). I didn't quibble as I was going to sell the place anyway. Good practice would be to come to an agreement about it with an amenable landlord.
you say it costs more sandy but i had htis row with eon and the rate im on is a standard tariff on their website and i can check it as the meter displays the rate
If I were a landlord, and a tenant had to gall to change things like that in my house, I'd be livid. Requests are one thing, but it's not the tenant's property to mess about with.