The cost of an iPhone 4 could drop in price dramatically this week as thousands of owners move to get rid of their “old” iPhone on eBay in favour of a new iPhone 5.According to eBay, more than half a million iPhones have been sold online since they have been introduced on the market. In the last year, an average of one iPhone per second has been sold via eBay with the online store now tipping a “big surge” of up to 70% in sales of the popular smartphone.

According to eBay sources the same surge happened last  year, when the iPhone 4 went on sale.

“Our figures show that savvy shoppers are ready and waiting to get their hands on the iPhone 4 at a cut down price,” Angus McCarey, Retail Director for eBay UK told the UK Daily Telegraph.

The smart phone market on the whole should see a surge in sales as the iPhone 5 goes on sale, eBay reports. During last year’s festive season, sales of the iPhone 3G exceeded the iPhone 4 as shoppers looked for great deals rather than the most up-to-date model.

The IPhone 5 is expected to be relased on October 21 in Australia. The revealing of the new phone is expected this week.