I actually wrote to Tropicana about the juice sizes and got this response, so if they're being honest then the price should be lower for the smaller bottle:

"We have optimized the size of our multi-serve bottles, moving from a 52oz to a 46 oz package. We have updated the design to modernize and make our bottle easy to open, pour and store. The cap no longer includes the induction seal therefore is easy to open, without compromising product safety, and contains 61% less plastic. The bottle also now takes up less space in the fridge and the slimmer bottle is easier to grip to pour.

"We’ve lowered the manufacturer’s suggested retail price (MSRP) of these new multi-serve products: $3.99 vs $4.69 for orange juice and $2.99 vs $3.39 for juice drinks. It is possible that for a brief time, retailers have not adjusted their on-shelf pricing. Please note that average costs may vary across markets and retailers, as is common with most consumer goods. "