I think the tone the tweeter/Xeeter wrote in implies he’s disappointed, flabagasted, maybe a little angry. This would imply he spent more money than he needed to and got more beer than he wanted, like you assume.

But for this to occur and him to actually agree to pay, what must’ve happened is:

• “Hey, can I check how much beer you get in a sled of beer?”
• "Yes sir, you get 96 beers in the sled of beer
• “Excellent. I’ll take one sled of beer, please”

Or maybe it’s a reduction for clearing out stock.