I've been thinking about the posts here, and it's a hard question to answer? At what price is it outrageous? I guess the answer is different for each of us, and it's probably a moving target.
Here in N. FL, cheap craft beer is $7-8 a sixpack, $9-$10 is more common, and some are at $11-12. So looking at the higher end of $12, that's $2 per bottle. Buy that same beer in a bar/restaurant and it's $6-8 (sometimes more). So 3-4 times the cost of drinking that same beer at home. 22 oz bombers seem to be $7-8 and up, they go in the bars for $15-20 ..... maybe more of a bargain than the 12 oz beer. 750's of an unusual, hard to get, or otherwise special beers are going to be $25-$30 or more.. but they cost more in the bottle store as well.
Hmmm, maybe I should be drinking more whisky at the bars. You can get a decent single malt for $35-$45 per bottle. Figure 17 ounce & a half shots in a bottle, so a dram would cost $2-3 at home, and a minimum of $5-6 in a bar, usually more. So 2-3 times the cost at home. If you move up to more expensive whisky $55-$100 a bottle, it may even get better. The dram from the $100 bottle costs just under $6 at home, probably sells for $15-20 in the bar.
Obviously, you're paying for ambiance & entertainment. I'm a cheap son-of-a b**** so it irks me to pay the high cost. So I don't do a lot of drinking in bars. The point where it gets outrageous is where you stop buying (at least except for rare occasions), as the OP said. For me, that point might be lower than most cause I'd usually rather be drinking at my house, or at a friends, rather than in a bar regardless of price. Besides the home brew is usually at home.