Hi
I'm sorry but..........:
When we have products options (size, weight*my case*, etc...) it's not a professionnal way to show the prices by difference. Everyone wants to simplify the purchasing on e-commerce (like Abantecart i hope). When you buy something in physical shop, you have the real price for "big size" and not difference compare to "small size"!! Except for promotions of course!!
If we put $0.00, shows on front page 0.00. When we have one product without options so $20.00 in front page and another product with $0.00, some customers could think "out of stock" (they're not supposed to know the differents messages of the states of stocks) and its opposit to the law of commerce. When you have a product "in stock" you must show the price but not in options!
I tried to put "+" but erase on options (possible with opencart)
With others free-software like Prestashop (i used before), Magento,........the prices what you show is the real price!!
So please, could you find a solution ! your freeware could be the "best" but this method is a big mistake!!
Regards (my english is not perfect, i'm French