I'm having our cake done through Food City. Mom works there, the bakery people know her, and I'm predisposed to believe this will ensure I get a little extra attention. But still, since our wedding is small I saw NO point in spending over $50 for a cake! The only drawbacks to grocery store cakes is that you may be limited on icing and cake flavor choices but you can do a plain white cake, deck with fresh flowers, and offer pastries or other small flavored dessert on the side. We're doing a sheet cake for up to 50 people, white cake/icing, and when the guest count is set, I will look into 1-2 platters of something fruity or chocolate.
I am getting my cake from there. They have a 5 teir for $214 and a 3 teir for $138(feeds 150). They are great in taste, and can do a good job on decorating. They have some really nice ones on display at mine. There will be so much left over, I will be using it for favors.
My sister had a very small wedding cake made from a local baker for like $99. The rest of her 250 guests ate Costco cake (the classic sheet cake runes lik $19 for a huge square one) IT IS DELICIOUS! They have some with fruit filling, some with cream cheese. All absolutely mouth watering.
My big dissappointment in reagards to Walmart Wedding Cakes is that they don't bake their own cakes. The layers come in frozen, then thawed overnight. and decorated. The choice of cake flavors is limited to white or chocolate. You can't ask for a carrot cake or a red velvet cake because they don't bake the cakes! I'm also not a huge fan of their rock hard icing.
If you have to get your cake at walmart get flowers from your florist and decorate it yourself. The people who decorate the cakes back there have no pastry schooling at all. They just follow a book, which I think takes the artistry and personalization out of it. It also leaves very little room for customization unless you choose one of the other cakes they have and say "I want THIS cake with Those flowers instead of "whatever flowers".
I say cross your fingers and hope someone competant is making your wedding cake that day!
On a side note: Fredmeyers that have a cake department can make nearly anything you bring them a picture of, and are nearly the same price as walmart cakes. They will actually sit down and draw YOUR cake exactly as you describe it. Instead of giving you a book and saying pick one.