alt Hacker News> Otherwise you're giving up 1-3% discount.
I always ask for a discount but for some reason I almost never get it.
The rational move then is to pay in as many installments as I can get without any additional interest. Then time itself gives me the discount. My actual money stays invested and I only pay later. My credit card gives me 1.1% cashback on all purchases. Inflation too does some of the work.
You shouldn't get a cash discount - cash costs the merchant MORE than credit card fees. You have to count all the costs of cash that credit cards don't have: counting, and recounting the cash and change. Then the manager counts and recounts everything in the back room at the end of the shift. Then the manager counts everything twice again to write up the deposit forms. Plus you need a cash register with the extra cash drawer that acts like a safe. Plus other security systems just to prevent robbery (this can get elaborate in areas where robbery is common). Those all add up.