Sydney developers have resorted to offering special deals amid an oversupply of apartments, dropping prices and restrictions on foreign developers.

The deals included paying 12 months of a buyer's mortgage, $50,000 "bonuses" and furniture vouchers —all aimed at solving the apartment glut in the capital. In addition, some developers have launched targeted social media campaigns to attract customers, according to a report by ABC News.

St. Trinity Property Group, for instance, advertised free mortgages on its select "luxury apartments" for a year. Arden Group, meanwhile, claimed to pay the stamp duty for buyers of its development in the north-west of the city.

Property analysts said the deals typically sprout in an oversupplied market. A total of 54,000 new apartments built in 2018 and 2019 would likely be listed for sale by the end of the year.

Developers would do anything to avoid cutting the asking price, according to SQM Research Chief Executive Louis Christopher.

"If they do that [reduce the price], it will reduce the valuations on all other properties within that development, and therefore the settlement risk rises accordingly," he told ABC News. "But buyers should be aware that they are still paying for it in some form, and it generally comes in the form of over-valuation."

Sydney posted a median unit price of $678,199 in May – down by 6% over the past 12 months. Some professional in the real estate industry, though, forecast that the property downturn in the city would reach a floor in 2019 and start recovering in the early parts of 2020.

The real estate sector needed a "hard dose of reality,” said Martin North, property analyst from Digital Finance Analytics.

"But from the data I'm seeing, investors are not interested in coming on board and the demand is not coming through," he told ABC News.

While average unit prices have dropped by only 6%, some pockets of Sydney such as Hurstville and Ryde recorded severe falls.

"In Ryde, unit prices have dropped more than 30%, essentially something that developers can't cover," he told ABC News.