These are exactly the kind of thoughts I like to see people having about Bitcoin.
How about £0? That's a solved problem too. In the parts of the world with a working, modernized banking system and proper competition.
I could chose to be part of those who got charged £1. I chose not to, and so did so many others, that where I live, finding a bank which charges you money at all to withdraw anywhere in the world is the exception, not the rule.
There may be merits to bitcoin (although I do admit I have very little knowledge, insight or understanding of the system), but you don't need it to have working banking institutions and free trade. That I do know.
Is it the same for my mother's credit card she got at the supermarker for club discounts? Probably not, but she uses another one outside the supermarket.
[0] There is probably some hidden fee in the conversion rate, but it seems to me a fair conversion rate, not unlike I would get at the post office.
[1] Personal cards