Less-wealthy Cariocas never take taxis. All residents are entitled to a Bilhete Unico. The "only card" transit card gets you a second mode of transit for no extra money to a bit more depending on the modes used among buses, trains, metro, ferry boats. Rio residents love to complain about everything increasing in price, but when the card came into effect about a year ago it was a great cost savings.
There was a great hue and cry when eggs and tomatoes went sky high last year but now that they have gone back down, ditto on garlic, no one seems to be happier. Eggs here right now are about 1.40US/dozen so not bad.
I think the most popular food item at McDonald's is the casquinha - ice cream cone. Cheapest thing on the menu basically. Whether the chain is McD's, Burger King, Bob's, Giraffa's or KFC, most residents don't patronize them. The food options and cost at the por quilos/kilos are just too great and a better value. One just needs to check your watch for the time and the menu outside the door which lists the varied prices per 100grams and at what time the prices change. Usually 11:30-Noon is cheap time and then either after 1:30PM or 2:00PM which has the lowest price points. Many por quilos might be at 2.20 or 2.40 after 1:30PM. The more expensive ones usually will have some fancier meat choices. Picanha and filet mignon instead of alcatara, for example. But every one will offer grilled chicken breast, chicken or pork sausage grilled and a few types of beef with lots of healthy veggie options. If you can get a great plate of food for lunch for 15-20Reais, much better than a small combo meal at the chains for 20-25.
One final mention as to food, fit Brasilians eat food and consider it as fuel for the body. The 1st world ideal of food bringing us pleasure or whatever - not here. And the base on the plate for everyone is rice, beans, farofa and some sort of protein. A fish filet, chicken thigh and leg or breast, beef, eggs and cheese, whatever with veggies. The fatter people you see now - we believe it is the invading US consumer culture with processed crap that it causing this - chips, hidden fats, etc.
Brasilians are like turtles - they can carry everything on their backs with a backpack. It is almost like everyone you see has these growths on their backs. As well as an added colchonette or foam rubber sleeping mat. Money on hotels - not. They travel, sleep with whomever they might faintly be acquainted and unroll the foam and go to sleep like sardines with one beside the other, more often than not, head to foot. Right now with Carnaval starting soon, there are even more of these tumors than normal.