To add my 2 cents on the bulk buying foods:
Pros - lower cost per meal (able to buy when on sale), more choices each night (more food in freezer/pantry to pick from), fewer trips required to the store
Cons - extra space/electricity, less fresh foods, harder to try new/random recipes (always trying to fit into what you already have).
Personally, we bulk buy pantry items, freezer veggies, and ground meats. Fresh/weekly buy milk, eggs, chicken, fruits and veggies. We don't have a deep freezer, but a large pantry, so that is part of what drives the choice for us.
As for the start-up costs, focus on only 1 or 2 items at first. So you've started stocking your pantry/freezer, so wait a month or 3 before replacing light bulbs. Spread the purchases out (while looking for sales).