Vat Charges on sales

Hi,

Just wanting some advise on something as im confused!!

When i Import goods from China i pay Vat 17.5% + the Duty of course which is 13.9%,

So say if i were to buy an Mp4 player for £15 im assuming i would work out the duty which would be 13.9% so the total would be 15.00/100*13.9= 2.08

Then £15+ £2.08= £17.08.

Would i then pay the Vat as follows 17.08/100*17.5= 2.99 + 17.08= 20.07

So the total price of the MP4 to import is £20.07

When i import it DHL would charge me or i would declare & pay this Vat & duty so when i come to sell it on for £60 do i then pay Vat on the difference £60- £20.07= £39.93

Or do i need to pay Vat on the entire sale of £60?

I hope all this makes sense to some one with more experience on the forum!

Chris.