This post is all my humble opinion and may be different than yours. Even with watching my families pennies, there are many items I would not even think about trying to make from scratch and would buy in a store or do without. Some because I just plain have no interest in learning how to make and others, that even if I had an interest, the result I'm sure would be such poor quality it would end up trashed anyway. You won't find me micro brewing my own beer, or fermenting juices to make wine. I'm not going to crack eggs in a bowl and whisk in some oil and make my own mayonnaise. Then there are some items, that are so outrageously priced (and yet I have bought them and been disappointed) that even with the time element involved, I prefer to make in my own home. When it comes to dining out, I skip things that do not add value to the experience.
Muffins and cupcakes: Even for those large ones, I can't see a reason for a single muffin or cupcake to cost $3.00 or more. Granted in a grocery store you can often get generic for $6.00 for 1/2 dozen smallish ones or 12 mini, but in my kitchen, I can whip up a dozen for half that much, in about five hands on minutes, and 18 minutes of baking.
Deli coleslaw: Unless it is a super sale, spending $3.00 on a small tub that barely feeds the three of us is pretty expensive. Add to this the fact that you may be buying the last of an old batch. I'd rather make my own coleslaw dressing with a bit of sugar, vinegar, mayonnaise and pepper. I don't have a cabbage shredder, but even buying a bag pre-shredded (not on sale) with my own dressing yields twice as much as the deli, and it is fresh and tasty. In summer, the pre-shredded is often on sale for $1a bag. As for time savings, I can whip up coleslaw, complete with the making my own dressing, in the time it takes to stand at the deli counter.
Restaurant ala carte side salads: Unless the salad is part of a dinner, I skip ordering. Usually a side salad is a bunch of iceberg lettuce, perhaps a few shaved carrots, a cucumber slice, and maybe a cherry tomato. Unless it is a house specialty made dressing, you have to add so much pepper to have any taste. I'd rather just enjoy my main dish and save the $3-$5 add on.
Restaurant Deserts: I am going to qualify this one though with restaurant deserts when there is not a pastry chef on staff. I have had some truly mouth watering deserts and house made pies, clearly made by someone that knows what they are doing and with a great cup of coffee, it was a perfect end to a meal. I'm talking the generic deserts that more than likely were defrosted and plated, or defrosted, warmed, and then plated, and you get the pleasure of spending upwards of $8, even in chain restaurants like Olive Garden and Applebees.
Breakfast add-ons in hotels: Many hotels have a complimentary continental or more breakfast. Then there are those that have the option of an up charge for on site breakfast. My experience, take a pass from this "bargain." I've seen charges as high as $15 per person on what appeared to be a bland buffet. When we were in Washington DC two years ago, we had the option of adding breakfast vouchers to our hotel for $15 a person. One of our days we decided to just eat a big breakfast before heading out for the day, planning to skip lunch and have an early supper later. Knowing other than in Union Station there wasn't a lot around for early breakfast, we just ate in the hotel restaurant. (We had spent $33 picking up breakfast at an over crowded Pret a Manger two days earlier, so a sit down breakfast was preferred) DH and I had the quite nice buffet, which ended up being only $13.99 a person, cheaper than had we prepaid. DD2, wanted French toast which while on the menu, wasn't on the buffet, and got an order with a side of hash browns for around $10.00. I suppose if you were trying to keep all your costs together, or were a business traveler, it would be considered a convenience cost.
I should add, when we do go out for dinner, we order what we feel like eating. I don't understand the purpose of going out to eat and then limiting yourself on options-I'd sooner go out less often if trying to be economical, than limit to only what is the lowest priced items. We tend not to drink our dinner, and maybe have a beer or glass of wine as we wait for the food to arrive, but most often just the one. When we meet friends for drinks and nibbles, we might have a couple, but have not been the type to sit for long stretches running a large tab. We are good tippers though, tipping at the full rate even if we are out at happy hour prices. What do you think is so overpriced you just don't bother to spend the money on? How do you balance eating out and going out with friends with trying to manage your budget?