It really depends on alot of things.
Firstly if sending to the UK and the item in question is marked as a gift and is below the $45 you should not be charged any duties. Please note this is not supposed to include shipping costs but sometimes the person sending will add the shipping cost to the value of the item aswell.
Secondly fees vary depending on who does the final delivery. For example if Royalmail did it then you will only get charge tax and a very small fee. If DHL, Parcelforce, UPS,etc did it they will charge upto £20 processing fees on top of the tax.
If importing from a store then use a Calulator like this:
http://www.dutycalculator.com/new-im...x-calculation/
Remember all the stores can not mark as gift.
Note the small text at the end of the page and you will see that it does no include the carriers additional fee which could be upto £20 in the UK.
However there are some unique exceptions, Yes-asia for example send games to a small company in the UK and then repackage and send out to you. This way there is no fees to pay. Hence why many items including soundtracks and Artbooks have a label saying"
This item is eligibly for free and tax free delivery". This include items upto $200.
Not sure about Play-Asia though, been charge tax and fees every time I ordered from them.