That's hardly much of a mark up IMO. I got 2 for Friday and 2 for Saturday without any drama at all and they work out at £62.50 each face.
With three dates now the market will be flooded with them and I expect they'll be a damn site cheaper than £100 a pop once the initial hoohar has died down.
Keep trying if it says sold out - they usually release more later in the morning, particularly when some sales don't go through (credit cards screwing up and stuff.)