My Vegas experience is largely as a local, so I'm not a great source for tourist recommendations. You've probably spent as much time on the strip as I have. I just know that one of the few positives about that city is that it's incredibly cheap compared to other major American cities. I actually just spoke to someone from San Francisco who was marvelling at how cheap the food is. But that person is an older person with lifelong friends there, not someone trying to party and such. The best advice I can give is don't grab your food from gas stations, tourist destinations and such-- I went to the ATM at a 7-11 near UNLV and the fee was around $2 as I'm used to; if you went to the Vons in that area, you could have gotten some cheap food. (The Smart & Final near UNLV may be your best bet. Of course, there are always places like Wal-Mart and more local/regional options like Sprouts.) I can't speak as to why a group like Boyz II Men is performing for free anywhere-- That's definitely not happening with major acts in Vegas. Entertainment may cost more than other places but the basics are really cheap.
That makes sense. A Lyft driver did tell me that staying in downtown Las Vegas is a very different, and much superior experience than staying on the strip.