I'm planning a way to make our server farm more efficient, and as such it will involve getting rid of the old servers at some point. If I decide to push to do this, how much do people reckon the following would be worth? To try and recoup some of the cost of implementing a new system, i'd be looking to sell the below:

HP DL 360 G5s with the following spec:

1 x Xeon 5405 @ 2Ghz x2, 8GB RAM, 2x 146GB SAS 10k drives
3 x Xeon 5440 @ 2.83Ghz x2, 16GB RAM, 2 x 146GB SAS 10k drives
1 x Xeon 5440 @ 2.83Ghz x2, 8GB RAM, 2 x 146GB SAS 10k drives
2 x Xeon 5130 @ 2Ghz x 2, 2GB RAM, 4 x 73GB SAS 10k drives

Fujitsu Siemens RX220

2 x Opteron 246 @ 2Ghz x2, 2GB RAM, 2 x 140GB SATA 7.2k drives

Fujitsu Siemens TX150 R4 Storage Server

1 x Pentium D 3Ghz, 512MB RAM, 4 x 500GB SATA 7.2k drives. Windows Storage Server 2003.

Overland Storage Snap Server 520, 4 x 500GB SATA 7.2k drives. iSCSI SAN/NAS device.

Note: It isn't currently for sale, this is simply a calculation exercise for myself.