Your price is still not right.
https://bitcointalksearch.org/topic/sold-bitmain-antminer-s7-150-off-coupon-025-btc-1271870
I can still sell you a coupon , even three. But the price is 0.2 BTC from piece, as you already know.
With one coupom you already win 30USD , by paying less VAT from the final price.
My offer is valid until Sunday evening. After this, the price is 0.22 BTC from coupon.
For example, S7 prize with 150USD coupon purchased for 0.2BTC
1650-150=1500USD
Shipping 58.02 USD
1558 +20%VAT= 1869,60 +86USD ( 0.2 BTC coupon) =1955USD
1955:4,73=413 USD GHs
without the coupon
1650+58.02=1708 +20%VAT= 2049 USD
2049:4,73 = 433USD for GHs
You win 20USD from each GHs .
From 3x S7 you win is 280 USD + 90USD from less paid VAT but you still want a cheaper price.