$300 server

Sorry if this is the wrong thread. 

My friend and have a single rack mount server we would like to revamp. It is atx and we would like to run a minecraft server along with a few other games. All we need is a motherboard, cpu and ram. Thanks for any help. 

Pick a computer out of the trash and take it's mobo/cpu/ram. done.

If it need to be cheap and rack-able. Check out all the used "dell cloud servers" on ebay. 

Mobo including quadcore Pentium, passively cooled, extremly low power consumption.

http://www.asrock.com/mb/Intel/Q2900M/

Then add RAM and one or two SSDs and that should do.

Core i5, basic motherboard (with room for expansion) and some basic memory.

http://pcpartpicker.com/p/zvKfGX

Potential changes include spec'ing up or down the CPU along with changing the quantity of RAM.

I find it hard to beat the prices of these systems. 

http://www.ebay.com/itm/Dell-PowerEdge-2950-III-3-5-Server-2x-3-0GHz-Quad-Core-16GB-4x-146GB-15K-/221655171556?pt=LH_DefaultDomain_0&hash=item339bad81e4

or
http://www.ebay.com/itm/Dell-CS24-SC-1U-Cluster-Cloud-Server-2x-3-00GHz-QC-E5450-16GB-Ram-4x-500GB-HDD-/181636939047?pt=LH_DefaultDomain_0&hash=item2a4a67bd27 

Very much this