This. Particularly the 'old charm' bit. A smile and a friendly, warm, even conspiratorial (if your agent seems to respond well to that) demeanor goes a long way. And if the bill in question is extra-large, and your request is extra-large, make up a story to back it up. Celebrating your 10th trip to town? An anniversary? Wanting to impress your wife/husband/boyfriend/girlfriend who is arriving tomorrow? For their birthday? (not your birthday, at some places that'll be in the system)... Smile, ask for what you want, make the interaction pleasant for your desk-person no matter how it goes (as soon as it sours you're out of luck), and tip accordingly. In my experience, in LV, money really does talk. So does basic people skills, so exercise both and enjoy the best the town has to offer.