Need a 1TB External Desktop Hard Disk

help me to get best deal out of these or suggest any other….
According to my pref.
1. HS18 WD Element 3160 – 500(GC) = 2660 BEST DEAL
2. Tradus Seagate Expansion 3499 (1500 CASH BACK). DOUBT ABOUT CASH BACK
3. Letsbuy WD Element 3200 – 320(10%) = 2880 (2 days back it was 2700) GOOD DEAL
4. Infibeam WD Element 3111 -155 (5%) = 2956 PRICE IS HIGH

thanks