Answer:
Unethical, but Legal
Step-by-step explanation:
An action will be deemed as legal if it is performed under the dictate of the law, that is it does not violate the laid down rules and regulations of the court. However, ethical behavior could be interpreted as actions showcased during interpersonal relationships which is usually characterized by fairness, openness, probity and other actions which are morally responsible.
In the scenario described above, the action of the California company in its sale of the computer program is not illegal as it pays in the long run to finance their purchase rather pay cash as advertised,, hence, there isn't an illegal act of lying in this contest. However, the company fails to be transparent enough by concealing the effect of income tax which they feel might put customers off. This action could be deemed as Unethical as probity and openness was not adequately showcased in their dealing with their customers.