Answer:
The Costco bag is a better deal as each pound is $0.65 cheaper
Explanation:
Let make the weight of each bag in a common unit
18.14kg = about 40 pounds (formula: multiply the mass value by 2.205)
Now find how much it cost per pound for each bag,
Costco: 49.99 / 40 = $1.25 per pound
Bulkmarket: 18.99 / 10 = $1.90 per pound
1.25 < 1.90