Upload & Sell: Off
Obviously this job IS the exception. When a client has rented 8000 sq. feet of space, and flying in 500 guests, AND feeding... maybe even boarding some of them, it's a big deal. I think you are looking at a couple hundred thousand dollars, easy, for this event not including the photography. For the parents, or the people footing the bill, money doesn't seem to be much of a consideration. If you cut your fee to the bare bone it probably won't impress them. My 2 cents is to go for it. Charge, but be sure that your results will please them. Hire the third person too.... it's part of your expenses, not your fee.
I had a logo when I first started my photo business. At some point I discovered that it really doesn't matter to the client. They either liked you and your pictures or they didn't. Today it's more about a nice web design than a logo. Business and economic classes are focusing more on the identity of a business or corporation with pro logo and a brief slogan, not the artistry of the individual. If you look at the history of the masters of photography, I would venture to guess that not one had a logo.