Fus10n, on 27 November 2012 - 16:31, said:
Don't sell.. always regret doing this.. there are always a use.. FreeNAS if you want to turn into a file server, monowall or pfsense and you can turn it into a router/firewall
I agree, I never sell my stuff either, but that may just be us.

Either way, I always cherish to have a fallback system, or in the case of retro use of computers many years down the road, you'll be glad to have working machines - if just for a spare part in another retro machine.
To add to this: I think that using a full blown system to run as server can turn into a waste of electricity quite quickly.
I'd either consider running the server on the main desktop that's turned on anyways and just "never" shut it down OR get an affordable secondary machine that's electricity efficient to run as server.
Could be a laptop, a netbook, nettop, etc... you name it.
Bonus for portable computers: they have their own USV onboard.

Pretty fly for a server.
Glassed Silver:mac