Can you provide some source?

I don't have a source, the impression was based on my subjective knowledge that my Czech friends earn significantly less than my Israeli friends.

I know a lot of people in both countries - 1000 euro/month is a nice middle-class salary in Prague, in Tel Aviv that's just barely making ends-meet, if at all (it's quite possibly that your rent alone will be close to that much, and not in a particularly nice apartment either).