But the time isn't really the issue. You aren't paying the man X to come over and stand around near your pipes for a few hours. What you're actually paying for is his service. You are trading the benefit of his years of training and experience for X.
The fact that he has to come over and waste time in order to provide you with the benefit of his skills merely INCREASES the price. That's why the more highly trained someone is, the more they charge per hour. You aren't paying for time. You're paying for the benefit of the investment of time and money that went into developing that skill.
That is why copyright law exists. So that results of skill, the fruits of which can be easily benefited from without compensating the creator, don't lead to violation of the same deal. The artist has just as much right to only allow people who have met his conditions and his X receive the fruits of his years of accumulated talent involving the cost (time and or money) of music training, the opportunity cost of going into a different profession, the cost of equipment, promotion etc.
Potential revenue is not revenue. I am not disputing this point. What I'm disputing is the claim that you should be allowed to receive the result of the artists work without paying the amount they agree to. You don't have to buy the album. That's totally fine. Their failure to convince you to is their loss of revenue. But if you download the album and not pay for it, you have broken a deal you knew existed, you have effectively, as soon as you finish downloading that album, turned "potential income" into "stolen goods" because you have received your end of the deal without giving the rightful owner their end and you are legally liable for that end. Like I said, if you don't feel the deal is worth it, you can just NOT get the album. But you can't have it both ways. You can't benefit from the service and not pay the amount asked for in exchange for that benefit.