1 x party in the park ticket ?

due to time wasters I have 1 pitp ticket, I had to buy 4 as I could not get them, I paid £20 each but have 1 spare, will sell for £15 just to get a little bit back of what I paid, If I had not had to buy them and got them for free I would not be selling it as I dont believe in doing that first to come will get, must be picked up tonight.