AMD Athlon II X2 245/250 - 2.8K approx
ASUS M4A78LT-M LE - 2.9K approx iirc
(Socket AM3, HyperTransport 3.0, 760G, DVI port, EPU for power saving, 6x SATA ports, Anti-Surge protection, Express gate, ...)
ASUSTeK Computer Inc.
2GB DDR3 1333MHz RAM- 2K approx
Seagate 500GB HDD- 1.7K approx
FSP SAGAII 350 - 1.5K approx
Cabinet from VIP/Zebronics/etc without PSU- 0.8K-1K
keyboard+mouse - 0.5K approx
17" LCD- 5.5K approx
APC 600VA UPS - 1.8K approx
Total- approx 19.8K
I have considered cabby+PSU price as 2.5K as i have tried to fit a decent PSU for stability/reliability.
Yo can get Zebronics or some cabinet with PSU for 1.5K, you save 1K but that is not recommended at all.
For an idea on prices-
http://www.deltapage.com/list/index.html