CathInfo.com

Well, yes and no:
Yes, there are plenty of companies online which I order various equipment and supplies from, but when it comes to bulk food (ie., 50 lb bags of flour, milk, pinto beans, wheat, etc), you would get clobbered from shipping costs if I were to order 500lbs of food, whereas the sect is local for pickup.
I see what you are getting at (giving my money to a sect helps them, however incrementally), but I guess I never dwelled on it much until you made me think about it.  
Hmm.

Hold the bus.

I've spoken about this MANY TIMES. How many of us can be completely self-sufficient? I mean, producing all our own equipment, material, supplies, seeds, and labor? If not, then, read my lips:

You will be supporting atheists, heretics, pagans and all sorts of infidels and non-Catholics.

There are NO Traditional Catholic options for 99% of the materials and equipment the average person needs to survive. In fact, it's easier to list the things which ARE available from Trad Catholic sources, than to list the things that aren't!

Unless you are going to a Mormon temple and putting money in the collection, you are not guilty of financially supporting Mormonism (paganism, heresy, whatever you want to call it). Spending the night at a Mariott hotel is NOT donating to the Mormon church. Yes, a Mormon owns the Mariott chain, but you are getting something for your $80. It's not a financial contribution. You can't deduct it on your taxes as a charitable contribution. Right?

God doesn't expect the impossible. Even in the 1700's, when people were much more self-sufficient than they are today, I believe it was morally acceptable to engage in commerce with heretics. How much more so today, when people aren't even 1% self-sufficient. But it's more than that. Most Catholics in the 1700's MADE THINGS and did useful trades. These goods and services could then be sold to fellow Catholics. Today, what % of men work jobs where they can point to something at the end of the day and say "I made that", "I fixed that", or "I did that"? All too few, I'm afraid. So we have to resort to non-Catholics to get goods & services that we need.

Anyone resolving to avoid "supporting" non-Catholics, or believing support of such individuals to be a sin, had better head to the woods and begin a new life as a naked, wild animal. Because you can't get food, clothes, shoes, housing materials, or anything of the sort from Trad Catholic sources.

And don't forget employment! How many of us would be unemployed if we could only work for Catholic organizations or companies? Over 97% of the men on this forum, I'd wager.