Get the following barebone
http://www.newegg.com/Product/Product.aspx?SID=L0zdJKESEeGamL4Q0CdmEg0&AID=10440897&PID=1225267&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-cables-_-na-_-na&Item=N82E16856119061
and put memory and HDD in it. 200$ total at most. That is enough to low HTPC.