Those looking to use a third-party resale website as a method to sell off their iPhone 4 and iPhone accessories may be disappointed with the offers presented to them by these internet outlets. Prices for this device are dropping due to a spike in owners getting rid of their devices in this manner, most likely resulting from plans to purchase the new iPhone 4S.

According to MSNBC, major web-based resalers such as NextWorth and Gazelle were reducing the amounts offered to users looking to trade in by significant amounts. The former changed its offer of $250 for any iPhone 4 to $200 for 16 GB devices and $215 for 32 GB versions. Meanwhile, the latter dropped offers of $250 and $225 for flawless 32 and 16 GB AT&T iPhone 4 units to $222 or $200, with $172 promised for 16 GB units in less-than-perfect but otherwise serviceable condition.

The news source reports that users selling their iPhone 4 units will fetch more for AT&T smartphones than ones using Verizon. This is due to the former's GSM technology, which is more prevalently used around the world – the latter's CDMA system is most effective in the U.S. and Canada.

Re-sold iPhone 4 units are inspected for quality by retailers, before being digitally and physically wiped of their internal memory, according to CNN Money.