If you look in my profile you will see a decent computer. It ran about $550-600, you would need to spend about $50 on a case and might spend more than the $75 I spent on my 23" HDMI LCD HDTV that I use for a monitor, so might come out to about $750 if you spend on those. This was bought about 6 months ago, so I went with a new 3rd gen i5 ($180 new, including shipping). I did buy some used/refurbished parts but they are holding up well.
MSI B75A-G43 motherboard, Intel i5-3470, 160 gb Intel SSD 2nd gen, 500 gb WD
7200 RPM SATA hard drive, DVD/RW with Lightscribe, 16 gb DDR3 PC1333 RAM
(4x4gb), AMD R7 250 2gb PCI-e x16 video card, 40+ all in 1 card reader, 700 w Power Supply