Go to any sporting event at any area and you're going to pay a pretty penny for beer. Some places offer you the option of a large or small beer, but one arena was duping according to a new lawsuit.

The below video was shot last Saturday (March 8) in Idaho at a minor league hockey game. The fan in the video shows that the $7 large beer perfectly pours in to the $4 small beer cup, which means both hold the same amount of liquid just shaped differently.

The CenturyLink Arena, where the video was show, is now facing a class-action lawsuit from four fans that say the arena's management defrauded attendees by offering different shaped cups but the same amount of liquid. The group is asking for $10,000 in damages.

The group's attorney Wyatt Johnson wrote in the suit:

While different shapes, both cup sizes hold substantially the same amount of liquid and are not large versus small in actual capacity. Defendants knowingly sold each of their beers in a similar manner at each event held at the arena where beer was sold for at least the last five years.

The president of the CenturyLink Arena & Steelheads hockey, Eric Trapp apologized on their Facebook:

It was recently brought to our attention that the amount of beer that fits in our large (20-oz) cups also fits in our regular (16-oz) cups. The differentiation in the size of the two cups is too small. To correct that problem, we're purchasing new cups for the large beers that will hold 24 ounces, instead of 20, for the remainder of this season to provide better value to our fans.

Do you believe that they just realized this?