My mind was absolutely primed by most of those In a Bangladesh market, a small potato bag costs 5 taka, a medium potato bag costs 7 taka, and a large potato

My mind was absolutely primed by most of those In a Bangladesh market, a small potato bag costs 5 taka, a medium potato bag costs 7 taka, and a large potato bag costs 9 taka. Yet, a single potato in that market costs 10 taka. How is that possible?