Yeah, I found a grocery store that charges a flat rate of $1.75 a slice. The cake itself wasn't great but the buttercream frosting was awesome. I don't know what Walmart charges (I think it's less, believe it or not) but I've heard
their cake actually tastes great.
My recommendation, though, is to ask around. I found a baker through a friend of a friend - she just bakes from her home, part time, and doesn't advertise or anything so I wouldn't have found her otherwise. But I am getting a 4-tier
fondant cake with two different kinds of filling for $135 - she charges a flat rate of $2.25/slice no matter what kind of cake it is or what she puts on it. And it tastes awesome! I don't even like white cake (that was one of FI's two
requests) and I couldn't get enough of the sample cake she made us.