Puzzle ZNWN 

Workings

Hint
# is worth 3.

Answer
14.

Reasoning
The values are: @ = 7, & = 4, $ = 8, # = 3, £ = 5.

But...

...you don't have to find the value of every symbol!

The rows add up to 80, which means that the columns must also add up to 80.

24 + ? + 17 + 25 = 80.

? = 14.