How much do you value your time at?
If your income is tied to your performance at all, you shouldn't be spending time in line. Anyone who runs their own company, contracts/freelances, or bills hourly should never wait in line if they can help it.
But, unintuitively - even if you're salaried, waiting in line is a bad idea. It kills your mind. Nothing gets done. Your production is lower - across your whole life - if you spend time waiting in line. You'll never be able to measure for sure, but I reckon the man who spends a few bucks a week to not wait in line gets promoted faster, gets recruited more, gets more job offers, and larger bonuses.
In other words - I think the ROI on paying to not wait in line is pretty good.
So, try this - long line. You're buying a coffee for $3. Go over to a staff member doing something else (not the cashier), and say, "Hey, can I just leave a five here and get out of here, and you settle it and keep the change when things calm down?"
I've had a 100% success rate with this. It's conservatively saving me at the very least 30 to 60 minutes per week, and costing me... I don't know, a low enough amount that it's a no brainer. Try it out. Not obnoxiously. Just be cool, pay a little bit to free your time up and get the hell out of standing around like a doofus.