We need to have Starbucks (and all coffee shops for that matter) offer the option to pay on a sliding scale so you can fill up your 30oz Yeti and pay accordingly. That would be too pro-consumer though.
Starbucks gives, restarted in June (per a reply to another comment of mine here), a 10 cent discount for using a reusable cup. It's not a sliding scale, and it's not a ton of money back. But it's something, and probably more of a discount than the paper cup would cost them.
