Can't agree with the 2-3 times estimate. That is way too high. You will not pay $30/lb for filet mignon..you can't find it. The point is, adjust. For example last week there was canned butter from New Zealand at $2.39/lb in the Bahamas Family market. Try to find that price in the US...the butter is every bit as good as any in the US.
Meats are mostly frozen (for example at Solomon's), and you will have to settle for lower quality than what you are used to. I have done a lot of looking and buying, but with lots of substitution in mind, and I would estimate you should get by with 1.5-2 times. Sometimes the simple things we take for granted, like potatoes, can be 3X, but use rice, which does not have that multiple.
The secret is to adapt.

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