£150 - did you mean £15? You can buy them straight up without an auction for 40, the price isn't going beyond that. A decent bit of ebay bidding and it'll be under 20.
I really don't know why you're trying to convince people a second hand 7 year old phone costs £150 but it's bollocks.
Running costs!?!! Charging a phone isn't running costs. You don't need a contract to use nfc.
Picking up a dirt cheap, second hand nfc enabled phone is a very viable solution for anyone who doesn't want to take their main phone to the match. Spreading misinformation and lies about the cost of one doesn't help anyone.