As good as any of us is at determining "what a job will take," there are always variables, nothing falls dead-on to-the-minute, and in the end, we are forced to admit that we are really basing our pricing on an average for any given task, regardless of how well or accurately that average is computed. That's all that's being done.
Well, each photographer works pricing differently, but the answer as to why dj's do not is simple. With what you do, each hour of work done results in a physically tangible and somewhat obvious result that is lasting, and is used again and again. It is easier to charge an hourly rate when this is the case. Doing an installe, what YOU are doing when a client is not present is obvious when they come back into the room the next time. Our behind the scenes event work is not like that.
In the case of dj's, the pre-event portion in essentially a non-tangible for the client. They get a piece of paper or an attachment delivered to them that is the itinerary for their event based on our meetings, and they have no way of knowing or comprehending what goes into it, and this time they are paying for is unsupervised by them and they can't really comprehend what is going in during this time. This is why a lot of dj's prefer to just "tell" clients, or even in extreme cases themselves, that they are not "CHARGING" the clients for this time, when in fact they are.
In the client's mind, they are getting a 4, 5, or 6 hour chunk of performance time for their rate. Even though they are actually paying for all the behind the scenes, that chunk of time contracted for is the only tangible they have to quantify and qualify our rate with. After the fact, that final product delivered, the performance time, is either going to justify the rate they paid in their eyes, or it is not. That is why many dj's, at least for appearances sakes, charge solely based on an hourly or flat rate for that performance time alone. Other dj's, like Tom and myself, prefer to educate them on the fact that yes - you ARE paying for more than the 4 hours you get the day-of. And there is nothing "wrong," let alone unethical about that.
That's why a 4 hour reception with 6 hrs of prep/admin time is charged (at least by me) the same as a 4 hour reception that takes closer to 10 or 15 hrs of behind the scenes time.
So while it might seem to some that our pricing is opportunistic, I would argue just the opposite - that for myself, and I am sure a lot of guys here, we end up EATING it on jobs more times than we end up making a killing and skating on by. The more intricate and involved wedding with more games and activities, personalized bridal party intro scripts, etc, is going to see us eat it and come out on the short end of that "averages" stick.
The alternative to this approach is what many dj's do, which is not have published or fixed prices or rates at all and develop varying and seemingly arbitrary (from the clients perspective, and even from mine in most cases) prices per-event. That is never going to be a path I am going to take, and I'm not going to line-item time and work in an effort to nickel-and-dime, so a flat-rate based on avg time per-event it is.
Sure, some weddings will have been easier for me and some harder. Nothing wrong with that.
Well, the pricing should change for service providers by event type, but I am right with you in that in the industry as a whole, these margins are in many cases arbitrary and have no real science or tangible justification behind them.
In my case, prices are based on hourly charges for both performance time, and behind the scenes work (based on an average per-event) and add in fixed costs and overhead.
That being the case, my price for a 4 hour backyard birthday party or BBQ and a 4 hour wedding reception for 200 people are the same with the exception of:
*An increased (simply doubled) hourly
performance rate that I figure as paying myself hourly because dj'ing and mc'ing a wedding is a LOT more complicated and takes a whole different set of skills.
*More pre-event planning/paperwork time. An additional consultation figured in for planning. Time for music editing, etc.
Those REAL WORLD differences per-event are why MY prices go up for a wedding, and it is far from simply a "magical" or mysterious increase based on the word "wedding."
Even my laughable profit margin percentage (which would be a joke in the eyes of many dj's) stays the same for a backyard BBQ and a wedding.
Figured that at my 4 hour reception rate of $750, with all of the admin and pre-event planning time and all the stuff that goes into an individual event I am making about $30 an hour - which, Mike, I'm willing to bet is a heck of a lot less than YOU bill per hour... (?)
STILL think THIS DJ "has it easy"?!?!