I went there for a conference last year for work..first off, you will have incredible time unless you gamble away your house.
I stayed at the Venecian, which to me was a complete waste of money, but that is where my work booked me. It was $200+ a night and was amazing, but you are never in your room. You can go to any casino you want, so you basically just pay that much money to say you stayed there.
I also went and saw Chris Angel....another huge waste of money, but still a good time.
The drinks that you get for free while gambling are just that, free drinks. You tip a $1-$2 at a time and you get decent drinks, but nothing high quality (who cares).
I spent $300 of my own money the entire time I was there, and it was all on gambling/alcohol.
As others have said, get a bus pass. Get a whole day pass each day. It pays for itself in just a few short trips. The strip is amazing at night, but keep in mind it is a few miles long each way. If you are drinking you don't want to be walking that beast.
I also ate at a place called "Seredipities" (sp?). AMAZING food and it was pretty cheap, like $15 for a huge meal (yeah that is cheap there). I got the steak sub with egg on it...it was probably over 2 lbs+ fries. Give that a shot for sure!
Have fun man.