Jamal al-Satal, head of Syria's Consumer Protection Society, told the paper that "individual purchasing power has dropped hugely," estimating it had decreased "by 80 percent since the beginning of 2011."
Satal attributed the decrease to high inflation as well as "corrupt businessmen who raise prices much more than the inflation rate."
Syria's currency has plunged since the conflict erupted, from an exchange rate of 50 Syrian pounds per US dollar then to 370 pounds this year.
The European Union and United States have imposed crippling sanctions on Syria, and at least half of the population is believed to be unemployed.
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"Consumers are unable to afford the high prices of products," Satal was quoted as saying.
"The solution is not to increase wages, because that would bring up inflation once more," he added.
According to Syria's Central Bureau of Statistics, inflation rose 39.7 percent between May 2014 and May 2015, and the consumer price index rose from 143 in 2011 to 430 this year.
A report published in May by the non-governmental Syrian Centre for Political Studies said three-fourths of Syrians were living below the poverty line.
More than 250,000 people have been killed in Syria's war and millions have been forced to flee their homes.