Hmm... I don't even like Jack White and for $15 that's kind of tempting.
The parking price and the price of a beer will be higher than the actual ticket price.
A thrifty person such as myself would metro to and from and then possibly purchase one Modelo while onsite.
If you were to fill a flask at home with a few ounces of alcohol, go into Union Stage and buttchug it for maximum impact, then entire the venue before the clear signs of inebriation washes over you, you could save even more money.