Are we allowed to sell Multiple Child Themes for one Item on ThemeForest ?

Are we allowed to sell multiple child themes for one item on ThemeForest ?
Lets say we have upload a theme on themeforest and we want to include multiple child themes for that one wordpress theme. Are we allowed to do that ?

I don’t think so because it would probably require the purchase of two items if it depends on the parent theme (hence multiple demos on many themes).