I sold my 2008 dual quad 2.8 with 10GB of ram, a 5770 video card, a GT120 card, a 500GB disk with 10.9 on it, BT/Wifi installed, and an SSD sled (kept the SSD that had been in it, it's in my other workstation now) for $1k even (well, $940 for the machine minus the GT120 on CL and sold the GT120 separately on eBay for $65)
I retired my 2008 Octo 2.8 to my father, he will get another 5-6 years out of that thing in his graphics design studio for sure. It's a 6 year old computer, still the fastest thing he's going to have there.
No one will buy a 1,1 (me thinks so) so it will just be here until its last dying days. 8 years and counting and it still keeps up with my work. When I start editing 4K it will act as a media server and thats it.