Larry some food for thought about some of the issues discussed in this tread. You mention you are going to make a big change this year. This change is going to be huge and is going to happen regardless of if you are open for TW.
For the sake of this post lets say the change is going to be a room and you budget it will take 200 man hours to change this room. Regardless of when this 200 hours is put in, before or after TW, it is going to be put into the house. Just because it is put in before TW does not mean that it cost 200 hours of changes to be open for TW. Now if you have to pay people over time hours because they had to put in more then 40 hours a week to get this change done before TW then you could count the cost of the over time pay to the cost of TW opening. Your quote earlier is "We spent nearly 4 times more to do the event than we got back in ticket sales... and that is a fact." I would disagree, you may have had to work harder during a shorter time but don't contribute the entire cost to being open for TW.
To open any house does require per hour operating expense. This would be your electric to run, employee hours, wear and tear on props and the like, if needed special insurance for this weekend, ect. All of these expenses could be contributed to being open for TW. These expenses and the possible overtime from the example above are the only cost in TW.
So then the point got brought up about the higher ticket price. Again I would refer the first part of this post that all changes did not equal your cost for TW. But you say you can't be open for less then $50 a head. You know the number of people who come and know your hourly operating expenses and yes you may not break even at less then $50 but that should be the only thing that determine the price per person, not the total of expenses to update which would have been spent anyways.
You mention in this thread that no house should expect to break even the opening weekend. And I agree on this. If you can break even the opening weekend you did not do enough changes and you house will not be around long.
If you weren't open for TW would you charge $50 your opening weekend cause that was the cost to get the show ready for those people?
So now it just comes down to the true operating expenses. If all the information taken into account above and to run the show for electric, paycheck, ect is above $50 per head is the best price still $50? Say charging $20 you lose money, what is the worth of advertisement to a core group of haunters. And for that mater what is the worth of a core group of haunter coming out say "It was a great show but why is the owner charging more just cause he can".
None of this even addresses the points made about the house not even being ready for TW so we get a 75% show at a higher cost.
It seems the people who come to TW are expected to absorb all the cost of changes which means you true opening weekend you might break even.