mwave offers the TP-Link 5-Port Gigabit Ethernet Switch, model no. TL-SG1005D, for $14.99 with free shipping. That's the lowest total price we could find by $3 and one of the least expensive gigabit switches we've seen. This "green" device supports IEEE 802.3x flow control for full-duplex mode and backpressure for half-duplex mode.

Update: mwave also has the TP-Link 8-Port Gigabit Ethernet Switch, model no. TL-SG1008D, for $25.99. That's tied with our May mention and the lowest total price we could find by $7.