He means that the local currency is set to depreciate by half in a span of a week. And the bottom might be far far lower.
different times - No.
1$ = 152,3₽ (buying 1 US dollar)
1$ = 85,7₽ (selling 1 US dollar).
Just because you pay 152₽ to buy 1$ doesn't mean you can sell it at the same price. At least banks won't buy it.
According to banki.ru the best price for selling US dollar now is 94,00₽.
Hope that clarifies it.