Actually since it is part 91 and they don't actually need an SIC is it really that bad? Yes, it would not make sense to take that job if you need the salary, but since no SIC is required and they are not asking you to pay anything, AND they pay for all travel expenses it means you are just flying to gain experience right? It also said if they like you it could lead to a full time position in the future, so that sort of sounds like an extended interview. Maybe I'm missing something, but it really doesn't sound like that bad of a deal for someone who can afford to spend the time once in a while doing a job like that. Though maybe I can see your point in the phrase "Our bosses prefer two pilots for some trips." But unless an SIC is actually required it doesn't really seem all that underhanded.