Undergraduate Pandora Ng, 21, thought she was getting a good deal when she transferred $80 to someone she met on online marketplace Carousell for two tickets to Universal Studio Singapore's (USS) popular annual Halloween event.
The original price for each Halloween Horror Nights ticket is $68.
"I had my doubts initially, but when I came across an account that had a lot of 'likes', I thought it could be the real deal," she said.
But the Carousell user blocked her number after the fund transfer was completed.
Ms Ng said the alleged scammer had tried to convince her that he worked for USS by showing her an image of a company work pass with the photo and details blacked out.
The police are concerned over a rise in such Halloween ticket scams this year that has involved more than $21,500 so far, even as the number of e-commerce scams has decreased overall in recent years.
With three weeks to go before the event ends, there have been at least 35 reports of online purchase scams involving USS Halloween tickets between Aug 30 and Sept 29, compared with 30 cases for the event last year.
One victim was cheated of $7,000, the highest single amount so far. The smallest amount a victim has lost was $45.
The culprits would either fail to deliver the tickets after receiving payment, or provide fake tickets.
Victims would discover they had been cheated only when they were later denied entry to the event.
The majority of the fake tickets were advertised on Carousell and Facebook.
The police received almost 250 reports of e-commerce scams in August, an increase of about 50 per cent over July.
But the number of e-commerce scams since 2015 has, overall, decreased yearly. There were 1,307 such cases from January to August this year. The number for the same period last year was 1,382; there were 1,393 such cases for the period in 2015.
A Resorts World Sentosa spokesman said: "We strongly advise our guests to purchase tickets to USS' Halloween Horror Nights 7 through our official website, or at our on-site ticketing booths".