Free and priced order tags by quantity?

Hi @emre, i see that post but i believe is not that i need, i ve already configurate that part of the program, my product crepe has 20 order tags that client can choose as flavours such as: ham, cheese, chocolate, bananas, etc.priced as free. Client can choose 3 for free and additionals must be paid.
I think what i need is somthing like this: Extra Option to include order tag quantity in Max Selected Items
But i cant understand how do i implament this.