All the HEB down south sell 50# bags of Mummes corn. Never new Mummes to ever bag corn in 40# bags. As far as a price, I would just call the store and get a price.
Just make sure it really is Mummes corn instead of "apple scented deer corn" I bought at HEB in Montgomery county last year. It was neither Mummes, nor was it apple scented anything. It was overpriced 50 lb bags of very dirty corn.
The reason I asked was I usually drive through Abilene around midnight heading to the lease and they are still open. Used them every trip last season and they were 50# bags around $8.50 a bag.