I'm about to open a cake business and my plan is to get a Vulcan convection oven. However, I'm worried now that I need one with steam to keep the cakes from drying out but they are so expensive! Am I making a mistake not using steam?

Unless you are going to make homemade French bread, don't worry about the steam.

You definitely do not need steam for baking cakes. I would be more concerned about using the convection fan for baking cakes and pastries. Does the fan have a shut off? Or at least a low setting?

Yep, no steam needed unless baking bread.