Ah, off the top of my head, the following:

1. Mandalay Bay's Libertine Social - interesting menu with some creative dishes, such as their fried egg caviar.
2. Luxor's Diablo restaurant - Mexican cuisine; not bad but probably something you can get anywhere else at much more reasonable prices.
3. Bellagio's Harvest Cafe/Rest - Standard American fare with some grilled items. Again, nothing spectacular and pretty average--not something I'd pay for, but comped is fine.
4. Bellagio's Yellowtail - You've probably been here but sort of Japanese with a tad of western fusion. I enjoy the offerings here, but, again, with the Vegas pricing, not sure I'd pay for it with my hard earned money. Comped is ok.
5. NYNY Tom's Urban - Kind of like an upscale TGIFs? It's food and edible on nice plates.

With the above, I think they're all within your budget criteria except for Yellowtail, which will likely be an additional $100, at least, after including the tip. If I were you, I'd go with the Libertine Social at Mandalay Bay (it's next to Stripsteak). Of course, as you're probably well aware, just ensure you charge the dinner to your room at the Aria.