Not necessarily disagreeing, but don't most folks mostly know what they're getting and roughly paying before they eat out? I don't get online and comparison shop my meals out before leaving the house. I kind of know quality and prices of my options before I go, weigh that with what sounds good at the time, and then make my decision. If I go to my favorite brew pub and prices are 10% higher, I might note that, but I'm not getting up and going elsewhere. And +/- 10% on a $100-200 meal isn't make or break, regardless.
I worked in restaurants entirely too long. I really should have stuck with brewing beer. But my last brewing job went "poof" without many options.
I'm not kidding when I've said I've seen it all.
And one thing I saw CONSTANTLY is "the guest who comes in with the 'Big Mad' face, has a miserable time for the entire meal, complains about absolutely everything, and then tries to get money knocked off the bill."
Totally the wrong strategy. If they came in as the "life of the party," was nice to staff AND very knowledgeable about food in general, they'd get some freebies. Maybe not discounts. But some extras tacked on. But it requires being really nice and knowing a great deal about food. Most people try the "be really miserable and see if that does anything" approach. (Hint: We laugh at those people from the pass line. They're pathetic.)
Here's how to order food at a fine-dining restaurant like a pro.
1) Find out who the executive chef is. The famous celebrity chef is never in the kitchen (unless it's Hubert Keller, who is an amazing human being). Learn about that exec chef. What is he or she known for? They all have a history. Nobody becomes exec without being in the business a long time.
2) Ask if that chef is expediting tonight. (He or she almost certainly is. If not, oh well. The server now knows you aren't the average schlub.)
3) Order the following, verbatim: "My [partner] and I have no food allergies or aversions. We'd like two appetizers, two entrees, a dessert to share. Chef's choice. Surprise us. Ask the somme to recommend a bottle of something nice in the [name your general budget] range."
Not once in a lifetime of ordering this way have we received the most expensive stuff on the menu. Not once. (But it is always a risk. Someday, I'm sure it will happen. I'm rolling the dice every time I do this.)
Often, the exec will make something off menu -- a dish from his or her childhood and similar. Sometimes, we'll get a "tour of the restaurant" small portions of several items. A few times, they sent a few bites of their entire menu. And charged us for two apps, two entrees and a dessert. (The last time this happened was at a Japanese restaurant in Las Vegas which was closing down the following week. We tipped a few hundred on a $100 check. That's how much food they sent. We were there for HOURS.)
Naturally, don't order like this at Wendy's. Or Crapplebee's. This is for great restaurants only. And it's only for people who aren't timid about food. Because there could be steak tartare, seared foie, and octopus involved (picking three things squeamish people never order). It's also not for people who are allergic to everything except water. Guests can't order like this and then ask for a hundred modifications. "But no gluten, onions, garlic, seed-oil, salt, shellfish or pork."
Worst case scenario, the chef thinks you're better than average guests and sends whatever looked best when today's food delivery was checked in. Best case scenario, chef is in a good mood and says, "Let's show these people what we can do. Showtime!"