Why don't you just buy a vacation package for Las Vegas? Great bargains nowadays plus they give you free play.
We have little ones (4 to 10 year olds), so the museums were a perfect fit of educational and fun. Plus, Oklahoma was within driving distance.
We also did 4 days in Austin and spent only $80 on entertainment. More museums and parks.
I don't gamble, so Vegas really isn't for me; nevertheless, I've been there on business and it's a lovely city. Lots to see and do, with some wonderful shows!