I never buy food at the stadium, its crap and expensive. I get food before or after.
I work in hospitality so I can understand (sort of) the prices that are set for food and drinks, hell I work for an international hotel and we charge $6.50 for an Extra Dry.
There isnt alot that can be done for the food prices that im aware of, but service is one thing that irks me to no end. I would send anyone staff member home on the spot if they were rude to guests, and I probably dont have the authority to (yet)
I also got asked for my ticket when going up the stairs. Kid asked me "can I see your tickets guys" and I firmly said to him, with out stopping "its alright I know where Im going". Dont smile, dont aknowledge them more then to send the message. Dont even let them know your upset, they wont challange you as they have no power what so ever, and if they are wrong (which if they challenged everyone who didnt show their ticket straight away, they would be wrong most of the time), they will get in more trouble for being undeservingly suspicious.
The 2 drink limit is an RSA thing, it depends on licencing aswell. The fine is massive and I can understand it too.
But it isnt hard for stadium catering staff to be polite and welcoming. Friggin smile, have a small chat to the guests and treat them as guests to your home. Oh and most importantly, know the product your serving. Bloody idiots!