Correct me if I am wrong, but shouldn't there be a quantity discount if 3 units are bought?
3 units x 4.25btc = 12.75 btc
Subtotal = 12.75 BTC
Coupon discount for 1 previous purchase = 0.10625 btc ---> 12.75 btc - 0.10625btc = 12.64375 btc
Quantity discount for (3-5 units) = 2.5% of 12.64375 btc = 0.31609375 BTC
Final total = 12.32765625 BTC As I read the OP, the 2.5% discount is on the 3rd unit only, not all 3. The 0.10625 btc is that 2.5% discount on the 3rd unit. A 0.1 btc discount for previous customers would show up in the coupon column, not discount column.
Sounds logical Keefe. Was a little confusing, but then I just woke up.