If I end auction early to sell to highest bidder at current price can I then adjust the invoice?

[mygirllollipop]

My buyer and I have agreed a price, they have bid and I would like to close the auction and sell to the highest bidder but it says at the current price, can I add more money on the invoice?
TIA

I think you can add money in the seller's discounts/charges section. Not sure if you'd still be covered by paypal insurance though.