You should have told him it was half empty and it would have got you in.They stopped selling them online a few months ago. In theory you can pay at the gate but in reality you would have to turn ridiculously early to actually get in. For the Porto game back in November I turned up almost two hours before the game and it was permit holders only. The steward said they had already sold out of their pay at the gate allocation despite the car park being less than half full.