I work for walmart, our 2 tier cakes come in their own box, the top part is iced on a cake board then slide onto a plastic thing that has columns that actually go into the bottom cake layer. I have yet to have anyone come back and complain about their cake not holding up. : ) Honeslty, I havent done a 3 tier yet. the one I did the lady wanted it square (which i wasn't supposed to do but did anyways, in which i put holes into the cake boards where i would put the dowels through,then assembled, popped the wooden dowels through and tada! it was done. put it in a box the lady loved it. Sorry I wasn't TOO much help.
But just remember. even though 2 tiers are $48 and 3 tiers are $125. they ONLY have white and chocolate. We can not put lace or ribbon on that you bring it. we can NOT put on fresh flowers or anything that isn't already in our bakery.
It's a good price etc if you get someone that takes their time on the cakes, if you dont mind one flavor, if you didnt want lace or ribbon etc on it, and if you're broke like me lol