Much easier to add incremental revenue with increased ticket prices than it is on a stadium expansion gamble. If there are, in theory, extra fans out there that could fill up an expansion, then the demand is there to play with ticket prices. Let supply and demand forces battle it out. If we still have excess demand, then expand. We are at the low end of ticket prices. That doesn't really tell a "we need to expand asap" story. I'd like to see a capacity crowd in a 70k+ stadium just as much as the next guy. But as long as we are on the low end of the pricing spectrum, there things that need to happen before we begin building a very expensive addition. Increasing prices is one of those things. If we can't sell out next year with a moderate price increase, then expansion may not be the greatest idea.
All of this assumes we aren't leaving loads of money on the table by not having more luxury suites and club level seating. If that's the case, toss out what I just said.