40th Birthday party, good food and lively atmposhere.
I think you are going to have a hard time on the Strip finding what you want at the price you want. Have you thought of doing a boirthday lunch? A lot of the higher end restaurants are open for lunch and have prices in your range. Here is a link for Mon Ami Gabi at Paris that fits your price range for dinner. You may also want to consider some restaurants off the Strip.
Mon Ami Gabi
3655 Las Vegas Blvd S, Las Vegas, NV 89109