I've been to Vegas exactly once, for my sister-in-law's wedding. We had our kids with us (then very young), so we weren't really exposed to Vegas night life. Neither the hubs or I are much for gambling, and we were fortunate that his father was paying our hotel stay and for dinner for the family every night. We took advantage of the free breakfast buffet offered by the hotel, and filled the mini-fridge with bread, peanut butter, fruit and dinner leftovers for lunch.
We went back in 2007, but I remember quite a few free/cheap things we did. There was the free nightly show at Treasure Island, something with moving statues at Caesar’s, and an aerial thing at Circus Circus. I had planned ahead, and had signed up for some free rewards card thingy at Circus Circus online, which gave us a coupon for free arcade tokens for the kids (I'm sure it was to get us to gamble while the kids were busy, but we didn't gamble). We walked the strip quite a bit and took in the sights for free, although I do remember splurging on ice cream cones once. Hubs and I spent about $10 altogether on the slots, and another $10 or so on tips, when we were doing the forced hang out in the casino time with relatives each evening. We'd feed a machine just long enough to get a drink, then visit with the rest of our group until we needed another one, then we'd sit at a machine and drop two or three coins until a waitress appeared.
Our relatives spent a lot more. They gambled, they shopped, skipped the free breakfast for fancy meals,shopped, bought a lot of booze, and paid for a lot of shows.
I'd never purposely plan a vacation to Vegas, but it wasn't a bad trip. Not my kind of place and it's in the desert southwest, an area of the country I worked very hard to escape. I just don't get the draw of such a consumerist mecca in the middle of nowhere, I guess. People watching also revealed a lot of sad, desperate people, trying to win happiness and instead only being rewarded with bankruptcy.