I remember reading a GREAT thread on doing a line of budget minded wedding cakes. For the life of me I can't find it this AM and I have got to leave the house soon for the shop. If anyone can find it, I'd be most grateful! I've got a couple of brides coming in very soon who are on VERY tight budgets and I want to offer them this option.
I don't think this is the exact thread you were talking about, but it's a start:
I also remember that thread, and I can't find it either. I don't remember who started it, but it seemed like a great idea at the time. I know that cakesdivine does this, so you might be able to PM her and ask her about her method.