Sell the cpu separate from the moherboard, but offer the memory with the motherboard. That gets you the best sales on ebay. QX9650 median sold price for the last 14 days is $138.00.
And that's fine but then what happens with the old case and drives? And what happens if no one wants the motherboard?
Typically, it is only enthusiasts who are willing to buy bits and pieces. But whole, working computers are sought after by all kinds of people looking for a replacement or 2nd computer.
Note too, the operating system license used on this old computer is an OEM/System Builders license that came with, or was purchased for this computer, it
MUST go with the computer (or at least the motherboard)! And that is per the "
legally binding" terms of the license
you agreed to abide by when you continued using the license on the computer. If you piecemeal out the parts, the license (and
all copies of the software) MUST go with the motherboard, or be destroyed.
If the current license is a "full Retail license" (and the vast majority are
not and this is particularly true of factory built computers) then you MUST either send the license with the computer/motherboard, or wipe the drives. If you wipe the drive, you can then legally use this "Retail" license on your new computer.
You never get your money back selling old electronics - piecemeal or whole. If you sell it piecemeal, you will not sell all the pieces and before you know it, you end up with basement storeroom full of old electronics no one wants that you can't toss in the landfills.
At least if you donate or sell the whole computer, you know someone else will give it good home, take care of it, and get enjoyment out of it like you did.