It's the HP T5735. It's second hand from ebay. I got the fat version that has an extra PCI slot and I put a Realtek gigabit NIC in there. It's fast enough for home use, it does not saturate with my 200 megabit link. I use a TL-WR1043ND as an access point and VLAN-capable switch.
I think that he means per month in electricity costs. ;)
Seems a little high to me, but it does make more sense.