Hi,

I asked the oystercard people if it was possible to set the top up
threshold higher than £5. I mainly use buses, live a mile from a tube
station and the local newsagent charges 80p for an Oyster top up.
Their response was:

"
Please be advised that unfortunately it is not possible to change this
to £10, however if you know that your card is below £5 and want to
top it up you can go to an underground station and swipe your card on
the yellow readers and it will top up, you do not have to make a
journey.

If you are not making a journey you will be charged a small fee however
this can be refunded from the ticket desk.
"

How much is the "small fee" for topping up? What advantages does this
have over just going to the ticket desk? Anyways I don't live near
enough to a tube station for this to be an option.