okay, say i would like to buy 5 s9 miners with power supply, does this mean i can use 5 (order coupon) ? in other words can i get more than 10% off from the total order
No
it is very simple math.
the s9k is $97.00 dollars the most you can discount it is $9.70 if you have 10% coupons.
so for instance I have 2x 41 dollar coupon total of 82 in coupons.
if I buy 1 s9 use 41 coupon I get 9.70 off and it will reject that second coupon.
if I buy 2 s9 use 41 coupon I get 19.40 off and it will reject that second coupon
if I buy 3 s9 use 41 coupon I get 29.10 off and it will reject that second coupon
if I buy 4 s9 use 41 coupon I get 38.80 off and it will reject that second coupon
if I buy 5 s9 use both 41 coupons I get 48.50 off it will use all of one 41 and part of the second 41 coupon.
you max would be buying 8 units 8 x 97 = 776 and you use 77.60 of the 2x 41=82 coupons.