how order_product table works out price

i use a 3rd party service that pulls all my orders from my various channels of selling

the problem is that when it imports from opencart the price is wrong

the software uses the order_product table price&tax

how does the following equal the true price of the product that shows at £4 (please see attachement for image of table)

The calculation they use is:
taxValue = item price * ( tax / 100)
price = item price + taxValue


any help is great as im going crazy about it

Any help?