If you're going to travel everywhere by cab, plan on a $50-$100/day budget just for that. If you don't believe me, go ahead and price out how much a taxi from MGM to Downtown and back again will cost you, just to get an idea. Truthfully, you're better off picking a hotel that's by a bunch of other hotels and traveling everywhere on foot.
And don't even think about Uber or Lyft. Those are subject to the same rates of taxation and various fees (like airport pick-up fees). In fact, in order to legally be allowed to operate here they had to submit pricing plans to the Nevada Transportation Authority, which is very much interested in protecting the cab unions. All of this means one thing for you: Uber and Lyft are not significantly cheaper. Now, having said that, they do have some advantages: A) no additional charge for using a credit card, B) significantly reduced risk of long-hauling (they use GPS-based mapping programs and so do you), and C) you don't have to tip.
Also, pick-ups are a lot more convenient when there are long taxi queues at hotels where some young enterprising casino employee will try to shake you down for another $20 to get you to the front of the line. (We'll get to that, too.)