Wow. You guys are like... really unhelpful.

Their default prices are 50 coupons per from Treasure of the Sage.

Considering you need 47/46 shards each the total cost (undiscounted) would be 2,350/2,300 coupons respectively.

With a 30% discount you are looking at 1,645/1,610 and if you are lucky to get a 40% discount it should be 1,410/1,380.