Know your competitors?
The Cover is going to be both the major expense and the decider.
From remarks from designer daughter .......who has clients in international food industry - she deals in telephone numbers and "pitches" for a contract. (I know she uses a photographer who charges £500/day just for a retainer!)
All this just for labels!
At the other end there are paste-ups for catalogues and price lists and here I guess you think of a number, keep it cheap and cheerful and don't expect too much by it.
OK you expect 50-60 hrs expense but must add a margin for that cover, unless you feel you will only have one chance then "guesstimate" a little less.
What a load of waffle from one with no personal experience but who just hopes to throw a few ideas into the melting pot