Honestly, for me it was just refreshing every time the connection crapped out. Nothing else seemed to work. I bet they're getting hammered now though so it may take longer than the hour I got away with at 11am.
I started over 3 hours with filling the shopping cart... I'm about to just give up, $100 isn't worth this much PITA...
Oh man, that's rough. According to Pahalial, above, they had to restart apache so it may be worth trying again in a while when they have things sorted out more and when the blank screen frustration's worn off...a bit.