[mikeash]

Bonuses and commissions can be really different. Sometimes they're just supplemental. Sometimes they're the real pay, and the salary is just a nominal token effort. For many jobs, expecting the lowest isn't realistic. You wouldn't take that job if you expected the lowest, because the lowest is unacceptably low and almost never actually happens.

Waiters get tipped. That's the expectation and the reality. Anyone who takes a waiter job not expecting to be tipped is deluded (assuming they don't work for one of the few places that ban it).