system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How much money do retail stores spend on credit card transactions?

I've always wondered how credit processing fees effect large businesses (and various size businesses).  Here in Oregon we have very large grocery store that does not accept credit cards.  It also seems more and more common for gas stations to have cash prices different from credit prices.  I carry cash for small purchases like a soda from a minimart, but how does it add up for the store owner if I use my credit card for my $1.50 purchases?

So I guess a perspective for my question is how much can a company save (assuming sales are unaffected) if they do not take credit cards?
gpt
I'd like to address the last part of your request:

> how much can a company save if they do not take credit cards?

The other commenters have done a great job explaining credit card transaction fees, but the answer to this particular piece of your question is quite subjective and somewhat intangible.  Businesses save money *per transaction* by accepting only cash - there's no doubt about that.  This is a great business model for your local ice cream parlor, barber shop, or small business where they tailor to a specific community.  Here's the kicker - how many transactions/customers are you losing because you only accept cash?  Many people carry little to no cash in today's digitally-driven world and therefore don't patronize cash-only businesses.  Businesses therefore need to plan accordingly, whether by having cash-specific prices (gas stations), minimum electronic transaction amounts (popular in bars/pubs), or pricing products/services accordingly to cover the expected transaction fees.  Credit card companies have obviously figured this out and have made themselves indispensable, ingraining themselves into the global economy and introducing strategic new products (cash back rewards, frequent flyer miles, etc.) and services (fraud protection, purchase protection, global helpline, etc.).  Hope this helps!