Hi everybody. I'm from Basel. I've been browsing through your forum out of pure anticipation of the upcoming match. There seems to be quite a buzz about beer prices (understandably so), so I thought I could clear that up.
Actually, I've never payed 10£ for a beer here in Basel. Average prices for a regular beer (0.5 l) range from 7 to 8 CHF (5.30 to 6 £). There are some rip-off bars in the centre that demand 7£ for a beer (including English / Irish pubs) but 10£ is definitively a myth. In a supermarket and off-license you get a beer for 1 to 2 Francs.
What is really expensive though is proper restaurant food. 20-40 CHF easily.
As has been pointed out in here, prices are much lower in neighbouring Germany and France, but bear in mind that there's not much going on there on a Tuesday night. Basel isn't Berlin either, but there are some decent bars and clubs, some of which don't close until the small hours, just ask some locals.