That used to be true, back in the 1980s, in the Soviet Bloc countries, because:
- blue jeans were the fashion trend then and there
- they were not available on the market, at all (not "sold out", not "in small quantities", not at all.)
- thus providing an opportunity for home-made imitations and for scarce (rare even) black-market goods
Now, that's a textbook example for Economics 101: high demand, extremely scarce supply - and prices shot through the roof, quite predictably: and yes, people were willing to part with a month's worth of wage to get that one pair of jeans (as @M.K. recalls in the comments). So, it indeed used to be true, literally: sell a pair of blue jeans and live like a king for a week.
Things that have changed in this situation since 1980s:
- Jeans are not the new hot fashion trend (perhaps a fashion trend, if at all)
- Import is unrestricted
- Supply is abundant
- And that all was true even before I could have ordered virtually anything from anywhere, directly, through the Internet.
In short, that specific bubble has popped not "some years", but twenty-some years ago; two major market changes ("paradigm shifts," if you will) have happened since. It's an amusing historical tidbit, but nothing more.