Second hand games and 'borrowed' games have already been paid for and the company who have made the games will have received their cut.
You don't pay VAT on a car multiple times do you.
Actually you do
Assuming you are a VAT registered car dealer then you pay VAT on only the profit element of the sale eg. you buy for £500 and sell for £594 then you would pay the VAT element of £94 profit to our good friends at hmrc so you would pay over £14
This is completely irrelevant however

Almost back on topic is swapping games or buying second hand game worse or as bad as piracy as this deprives the industry of much needed revenue
For the record I have never owned a chipped console or pirated console game but did used to download ever single PC game as soon as it was cracked even though i probably only ever tried about 1 in ten of them