I'm afraid the spot price of EC2 has never been even close. EC2 GPUs are nVidia anyway, which don't have the specific on die instruction that made ATI/AMD card

I'm afraid the spot price of EC2 has never been even close. EC2 GPUs are nVidia anyway, which don't have the specific on die instruction that made ATI/AMD cards so good for mining back in 2010-2012. That's all been superseded by ASIC tech which is already in a race to smaller and smaller feature sizes. The math can be most easily done at mining.thegenesisblock.com