Final answer:
Vanessa prefers to avoid sunk costs which are costs that have already been incurred and cannot be recovered; instead, she should focus on opportunity costs and the marginal benefits of her current and future choices.
Step-by-step explanation:
Vanessa would rather expend other costs than sunk costs. Sunk costs refer to money that has already been spent and cannot be recovered, as exemplified by Selena's decision to buy a movie ticket and realizing the film is terrible. Staying to watch the movie involves an opportunity cost in terms of time that could be spent doing something else. The key takeaway is that one should focus on the marginal costs and benefits of current and future options, rather than on costs that have already been incurred and cannot be changed. For example, Eryn might consider the implicit cost of lost leisure time if starting her own firm would require more hours than her corporate job.