I have a customer request for a cake and was hoping someone can help me out she needs it to be for 30 people and she wants a round cake what size would I need? it will also be covered in fondant with fondant polka dots what should I charge? Thanks

A 10"x4" round will serve 35-39.
I'd charge about $55-75.

A 10"x4" round will serve 35-39.
I'd charge about $55-75.

I'm not sure where you are in Middle Tennessee. I am also in TN, but more toward East TN. What you should charge is going to depend on where you are at. I live in a VERY small town. I'd probably only charge $25-$30 for this cake. But that's only because that more than the going rate around here.
If it were buttercream instead of fondant, I'd probably charge $20.
Flat out, if I charge more, there's no business.
But if you are more in the larger areas around Nashville and such, you can get away with charging more.
I say find out what others are charging and go from there.