If I was hosting a shower, I would pay for a pre-made KIT to create a diaper cake. That would cut down on the shipping costs, as you could probably pack it in the $12 flat rate. I say that because I was going to make one for my friend, BUT in order to get a decent price on diapers you have to buy 200 diapers at Costco. I tried to buy 20 at the grocery store and it was like $14. What about a kit? Let people add their own "extras" and just send the basics - the diapers, rubber bands, plates and a "pattern" with design ideas and instructions.
I would check what is already on etsy. It's been my experience as a buyer on etsy that the best sellers on etsy are actually selling to other etsy/DIYers. Patterns, supplies, etc. I am perfectly capable of rolling diapers and creating my own cake, but I'm not buying a super-duper case diapers to achieve it (plus, don't they use multiple sizes?) If you think about that angle you might have something. I'm not buying someone's $150 diaper cake that I can make for $50 (Someone might if they have no artistic talent, and that's fine!). But I WOULD pay $50 for all the supplies and just add my own design extras and pacifiers or whatever. I just don't know if buying diapers in bulk and re-selling them has enough of a profit
