Disagree on Variance
It all depends on your assumptions.
The Standard Deviation (square root of Variance) for BS is about 1.12 and doesn't change with the level of play. By applying Rubin techniques (full tables resulting in fewer hands per hour, hand-held resulting in fewer hands per hour, playing slower resulting in fewer hands per hour, betting to comp level only when the PC is watching, etc.), one will be playing to a much lower average bet level per time interval. That will result in both a much lower cost and effective SD (& Variance) than playing it straight.
Responding to the basic question, a typical casino will give back in comps about 40% of the assumed loss of the player, based on the average over all players. Even without Rubinizing, this results in a substantially positive expectation for the BS player, assuming the player was going to spend the money for the room, food, etc. if not comped. By applying Rubin's techniques, Expectation can be increased considerably.
All of that assumes one is looking at net results of a vacation trip to LV, not trying to make actual money to live on.