Ive been to vegas a few times but never on NYE.
DOnt buy tickets online imo, first theyre not always legit, second sometimes theyre more expensive than admission fees, and youd still have to wait in line for hours with them anyway. Clusb sometimes distribute those passes for free, check with your hotel.
EIther go wait in line or reserve a table if youre willing to spend the money. Id imagine NYE would be bad for that, so maybe do the clubs thing another night.