McGee is a strange guy.
I think he saw this in a movie. With that being said, he does get Dollarnaire credit for going to Marshalls. If there are any Nuggets fans in the San Francisco area, you still have time to make it to Marshalls to collect your tickets.
More likely, a Golden State fan will find the tickets and root against the Nuggets, but it is the thought that counts. You can also pick up a nice polo for $29.99 and some white tees for $9.99.
If you prefer to go old school, I am sure there is some ECKO and Roc-a-Wear gear available as well.