I think $10 USD is about 6 Euro these days...
Prague is fairly expensive these days though, I think. My wife's parent's were stationed in Germany in the 90s while she was in school and she visited and said a beer was like 30 cents US or something. When we went last year it was like $5 for a Pilsner Urquell or whatever, $6-$7 for a pint of basically craft beer draught at Pivovarsky Klub and then $10 for a bottle of Sierra Nevada.
Viva la velvet revolution, I guess. Basically US prices. Tokyo is like US prices * 2, so no complaints.