Two things. First, you can't just "sell tickets" any more, it needs to be integrated so that you have an accurate account of your inventory, other outlets can sell tickets from the same pool, etc. It's no longer a case of picking up a bit of paper from the pile and putting it in an envelope.
Second, if you haven't even heard of transaction-based licensing then you are unlikely to remain one of the largest suppliers of software for much longer.
The point is that the ticketing software "cost" is an operational cost. The bizarre thing here is that the club are only adding THAT operational cost ( the cynic in me says it's because "they can get away with it" ). Why not add in proportion of the cost of electricity to run the system, the cost of smart cards, a little bit of the water bill etc etc etc. No, the product on sale should include the operation costs of the club. Ticket booking fees are nothing but a sly way of increasing the price and it's wrong that the club should jump on such a shameful bandwagon.