BB Bastard is actually cheaper than Metal Tech. When you work out the cost per BB, you're paying $0.00652 from Metal Tech when you buy a half case. When you work out the cost per BB from BB bastard, you get $0.006 when you buy one bag. 2500 BB's for 15 dollars compared to 36000 BB's for 235 dollars.
If you buy equal quantities, then you would save 19 dollars, in which you could buy another bag of BB's with from BB bastard.
All prices are before tax and shipping.