It's still mostly BS.
I hate when people cite these things..
Ones income needs to be enough to support expenses, but using them as an argument is futile.
Everyone spends additional time to ready themselves and travel to and from their jobs. Hell, even students have just as much extra work outside the classroom.
A
company has to consider these things in order to attract employees and therefore pays them accordingly. However, these things are NOT the concern of a company's
clients. The client wants the service for the best price possible and needs to be sold that price with a more tactful approach.
Another futile argument:
"The Professional DJ is also more likely to have extra or backup equipment even in the event that any equipment fails. The Professional DJ will understand how to size the amount of sound reinforcement needed to fit the room that your event is held in. The Pro will also know the best way to set up the equipment to not only be efficient, but to look tasteful and not interfere with the flow of your event."
This is just more rhetoric that makes the DJ feel justified, but the client doesn't care about. Thousands of successful events are completed every week that don't follow such technical practices as by these loosely termed "professionals".
Also, nobody cares that you
chose to create an inventory and approach that is costly to put to use.
The bottom line is that it's up to you to determine the best balance between what you want to provide and what you need (not want) to charge to make it profitable. You're not going to land every gig and you're not going to convince everybody that your way is right. If you need to create an entire page or engage in a lengthy discussion to explain your prices to a client, then
you're the one that needs convincing.