This is a good point. I know that when i had a job moving furniture a little extra "incentive"($$$) would make all the difference in me dropping it on the curb like the invoice said or taking it up three flights of stairs, through a narrow bendy corridor, even assembling whatever it was.That's a really good price for 3/4" where I live in CA. When I ordered my 1/2" glass, I called Glasscages.com and it was still going to be more with shipping and I still needed to drive 2 hrs to pick it up at their delivery spot in CA. I called a local glass shop who ordered it from a larger glass company near Fresno. The local company delivered right to my door when it came in.
In your case, that chunk of glass is going to be heavy! I bet if you worked it out with a local company, showed them pictures of what your building, or having them come for a free estimate or measurement, they would deliver it as well. If you get your sealing area prepped, bet they would even consider helping mount it into place, just because of the cool factor!!!