Fitting the bill of a total of 7 drives (parity, 5 data and a cache):
Case: Nexus Prominent 5 http://www.amazon.com/gp/product/B0057J90QE/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A21UKLVMUAO7H3
Drive Cages: 4 in 3: http://www.amazon.com/gp/product/B004IMKTY8/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A23NVCSO4PYH3S
3 in 2: http://www.amazon.com/gp/product/B004IMF0J2/ref=ox_sc_act_title_3?ie=UTF8&psc=1&smid=A23NVCSO4PYH3S
Motherboard with 7 sata: http://www.amazon.com/ASUS-240-Pin-Motherboards-F2A85-M-PRO/dp/B009F1DTLM/ref=sr_1_1?s=electronics&ie=UTF8&qid=1393985358&sr=1-1&keywords=Asus+F2A85-M+PRO
CPU/APU: http://www.amazon.com/AMD-A10-6700-Quad-Core-Processor-AD6700OKHLBOX/dp/B00CPLGEFM/ref=sr_1_3?s=pc&ie=UTF8&qid=1393985557&sr=1-3&keywords=AMD+FM2
Ram : 8 GB of DDR3 2400 @ $130.00
Power Supply: 450 watt @ $80.00
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700.00 + tax
Just add drives and license.