It takes 5 mins to get one, and then you just feed a tenner into the
machine when the barriers say you are getting low.

...which TfL get to keep and earn interest on.

Oyster in its current form is not suitable for very infrequent
passengers. There is no excuse for blatently ripping these people
off. 2 quid was expensive, but 3 quid is offensive.

No. There is a *perception* that Oyster in its current form is not suitable
for very infrequent passengers. There is no minumum balance on the card.
Only put a fiver on if that is all you will use all year. You don't have to send
away your passport or have a credit check to get one - you just go to a tube
station and ask for one. You don't even have to fill in a form if you don't want
to. Its just plain old fear of change.