I'm wanting to run a promotion on Seeds buy 5 packets and get the 6th for free.  I've tagged all the seeds in Product Tag so the promo is buy 5 from that Product Tag get 1 from the Product Tag. However it doesn't choose the cheepest item out of the Products added to cart. How do I get it to automatically choose the lowest price items?

Also I want the promo to work for every five items, so if they buy 10 they get two free. Is there a way to get it to repeat each time? I've added two more rules (buy 10 get one free/buy 15 get one free) but I'm wondering if there is a better way to set this up?

And finally is there a way that the promotion can show up on my ecommerce under the items it appiles to?