Obviously you need some mathematical help so let me serve as your teacher. He is getting 800 mg for $18. If you devide [SIC] $16 by 800 you get around $1.00 a milligram. $1.00 is a lot cheaper than $18. So he is paying 80%> less than you and pocketing the other $14. Originally Posted by PA DaveWTF? $16 for 800 mg is $0.02 per mg. 800 mg at $1.00 per mg would cost $800.