Bunnies are active in the mornings and evenings, so after 4pm isn't a problem for them. They sleep a lot during the day so either mornings or evenings work well for them.
Can you source your feed from a lower priced source? Where are you getting it from now?
Here we feed an 18% protein 'performance' pellet since that's the only bunny pellet that the feed store brings in. (It's Hawaii, all alfalfa is shipped in) It's in 40# bags and I can get 50# of rolled barley for the same price so about 10 - 15% barley is added to their ration. Since the feed is by weight and not volume and the rolled barley is 'fluffier' than the alfalfa, there's more barley by volume for the same price as the alfalfa so it's less expensive than the bunny pellets. Sometimes we get 'alfalfa cubes' which are less expensive than bunny pellets and give them to the bunnies for chew toys.
The bunnies also get a lot of forage since that's free, but I don't know if you'd have that option in your area at this time of year.