My gaming computer is worth $2,500, and the other 4 computers in my house are worth $700 and lower. These are all computers I haven't upgraded after building, so these are final costs.
The cost of all of these computers combined is $4,100, and my networking gear on top of that, from every wireless card I've had to get, Ethernet cards, cables, router, and DSL modem adds $400 to it, so about $4,500 for all of my computers.
My router cost me $200, my Ethernet cables costed me another $80, an Ethernet card for PCI was $20, and some 108Mbps Super G MIMO with SRX cards for 2 computers cost me $100 total. Two of my faster computers that can handle internal Wireless cards got the wireless cards, my gaming computer is equiped with Gigabit Ethernet built-in, so it's set with 1000Mbps Ethernet. My slower computers have hardwiring to them, as Wireless kills the CPU at the speed my Wireless works at. My PS2 is hardwired as well to the router.
So yeah, a bit of extra jabble, but the total cost of everything comes out to be $4,500 for all of my computers, and only $2,500 for my gaming computer.