In this case, the comparison is made by adding the inventory numbers, and comparing the two results.
We have:
Inventory Categories Cost Data Market Data
Cameras $10,007 $11,067
Camcorders 8,702 9,002
DVDs 11,073 9,773
Cameras $10,007 $11,067
Camcorders 8,702 9,002
DVDs 11,073 9,773
Totals: $29,782 $29,842
As can be seen, the two values are very close, which is explained by the higher cost than market data for the DVDs.
In that case, the difference of $1,300 is a loss, and probably should be entered as an expense.
The only way for that condition to happen is that price changes in the market place occurred before the inventory was sold. So, that inventory relative to the market will be sold at a loss. In the case of electronic devices, once market prices are lowered, it is rare to see increases.