So personally I pretty much just use a credit/debit card for most purchases, but cash is not uncommon, and checks are often used for paying rent to landlords or some small businesses. Then there are money orders which I know nothing about pretty much. But wondering if there is anything else, and wondering what people do for larger transactions. The only other thing I can think of is direct deposit, or wire transfer (if that's different from direct deposit).

Say there are two small businesses doing a transaction. Business A is buying 10 products and 1 service from Business B, for a combined total of $10,000 (case 1) or $100,000 (case 2), $1M (case 3), and $1B (case 4). I chose these four cases because $10k would be a pretty sizable check, while there are examples like a contract between Sprint and Apple (or something like that) for $2B recently.

I'm wondering for these different "scales" if you would (a) pay in cash, (b) pay with check, (c) direct deposit, (d) wire transfer, or (e) something else. I don't think you would use a debit or credit card here, but I could be wrong. If it's (e), I wonder what the typical options are or ways of paying.