blueish swede
Well-Known Member
The thief didn't buy anything as there has to be two willing parties to make a sale, in this case a vendor and a retailer. So he stole £30 cash plus £70 of goods at retail valuation.
They have lost £70 of stock because they have not received any extraneous funds to cover it, just as if a member of staff had given it away to a mate.
The shop received £70 for the goods, the asking price. The source of that £70 is irrelevant to the transaction. There is nothing special about an individual currency marker, be it a coin or a note. It is fungible and is equivalent to any other coins and notes of the same face value, both individually and in combination.
If the man had had a crisis of conscience later and returned to the shop and gave them £100 back, how much would the shop have lost? Nothing, they received £70 for the goods sold and had £100 returned to the till.
So the answer is £100