Nice, very nice I7-920. If you had listed this one a year ago, you could have done quite well, today, I don't think you'll get the $200 others are saying.
There just aren't many guys interested in spending that kind of money for an i7 when current Intel products out perform it, plus new ones on the way.
I do think that you could get $160-$180 for it, though.
The motherboard, I'd say in the $90-$110 range, maybe even $120, for the same reasons. Anyone wanting to spend money in that range is going to probably look at the current crop of boards and processors.