More than 600 breweries in one convention hall. More than 3,000 beers to try. The Great American Beer Festival is a must for Colorado beer lovers. It takes over the Colorado Convention Center in Denver through Saturday. Sure, tickets sold out nearly instantly. But prices have been dropping on the secondary market, and as of last week there were hundreds available at website StubHub for $10-$30 above the $75 face value. If you’re reading this, you already missed Thursday’s session, but you still can make the sessions at 5:30 p.m. Friday and noon and 5:30 p.m. Saturday. Can’t go? Follow the action at my blog, blogs.gazettedev.gazette.com/pikespub, and on Twitter, @Scottrappold.