When I tried to make fishing tackle for a business I did it this way:
I paid all excise taxes from the wholesaler. Didn't want to mess with it and easier to have a receipt saying it was already paid.
Overhead costs were minimal, I did all the work at home so no additional costs for electrical, rent or anything else. Bagging was $0.07 each, bought in bulk and printed my own cards.
I picked one shop and only supplied them. In my case I was making spinners.
Price I sold them for was based on what I need to make and keeping the price lower than most other comparable products.
I never did make any money at it but the shop I worked with only bought from me for 16 months or so.
As for my time, if I calculated that in I would have had to charge a lot more than anything in the store.
Best advice, don't get in over your head to the point it is no longer fun.
You can make money at it and keep it fairly simple but trying to get rich off it will turn your fishing time into working time. Maybe the shop that wants you to put the stuff in there will hire you to make them so they can sell them. Is the best of both worlds if they will do it.
I love taking my kids fishing, now if I could just manage to fish at the same time.