MANILA, Philippines - Days after the historic sin tax reform law was implemented on January 1, retail prices of cigarettes either stayed the same or rose significantly in Metro Manila.

Some stores kept prices at pre-sin tax law levels, while others jacked up theirs, a quick survey by Rappler found.

In Manila, convenience stores and supermarkets retained prices, but street vendors more than doubled selling prices.

Street vendors along Vito Cruz -- a key station of the Light Rail Transit and in close proximity to schools and establishments -- for instance now sell popular Marlboro and Philip Morris brands at P4 to P6 per stick or P80 to P120 per pack.

Sari-sari stores in villages meanwhile also raised their prices, but not that much. Philip Morris and Marlboro prices in these stores went up from P35 to P45 per pack; Hope from P25 to P30; Winston from P25 to P30; and Fortune from P15 to P20.

This means that Marlboro and Fortune now sell for P2.25 and P1 per stick, respectively, in sari-sari stores, compared to only P1.75 and P0.75, prior to the implementation of new sin tax rates.

Expectedly, these products will be more expensive in convenience stores.

Some of these stores said they still don't know how much the new prices will be.

“We need to wait for new stock before we can increase prices," a clerk from one convenience store near Glorietta mall in Makati City, told Rappler.

But some speculated that with the new tax rates, the prices of cigarettes may triple. A Marlboro pack may be priced at P140 to P180 once new stock comes in.

Filomeno Sta. Ana, executive director of the Action for Economic Reforms, an organization that helped the Finance department in the number-crunching during last year's sin tax debates, said some stores are selling brands "at a loss."

“We noted that some brands are being sold at a loss, or some items are sold at P25, less expensive than before.

“There are also some shelves that are empty now. Did the manufacturers pull out stocks that it plans to sell at higher price later? We don’t know. We are observing how the manufacturers will behave after the law is implemented.

“The assumption during the sin tax bill deliberation was that the cigarette and alcohol producers will pass on the incremental taxes to consumers and retain their base price,” he said. - Rappler.com, with reports from Ramon Calzado