← Back to context

Comment by matheusmoreira

16 days ago

> You shouldn't get a cash discount

Maybe, but "should" has nothing to do with it. Either I get one or I use my credit card.

> cash costs the merchant MORE than credit card fees

That's not my problem.

None of this is your problem: you are not a merchant. What is wrong is the analysis of various people who think cash is cheaper and thus get mad at not getting a cash discount. It is also wrong that a number of merchants are bad at accounting: they think that cash is cheaper by enough to be worth a discount - but this is not your problem either.

Just pay with a credit card, it's the optimal way by far (float, flexibility, rewards). No need to overthink it.

  • It's worth to think about it a bit, especially in larger purchases. Significant discounts on the order of 5% to 10% can easily beat all credit card benefits, and not taking advantage of it leaves lots of money on the table.

    I have a little lookup table for this. Interest free installments mapped to cash discount necessary to beat the credit card. I just look it up.

       1x -> ~1.9%
       2x -> ~2.3%
       3x -> ~2.8%
       4x -> ~3.2%
       6x -> ~4.0%
       8x -> ~4.9%
      10x -> ~5.7%
      12x -> ~6.6%
      18x -> ~9%
      24x -> ~11-12%
    

    These numbers are actually conservative. There's a lot of credit card benefits that weren't priced in. I add a couple percent to the required discount numbers and round it up to compensate.

       1x ->  4%
       2x ->  5%
       3x ->  5%
       4x ->  6%
       6x ->  7%
       8x ->  7%
      10x ->  8%
      12x ->  9%
      18x -> 12%
      24x -> 14%

    • Mathematically you are right. However those interest free payments are generally setup in such a way as to make it highly likely you won't pay it off by the end of the interest free period. The bills they send contain the minimum payment - designed to get you past that time. I don't trust my ability to get the fine print right - it only takes messing this up once to destroy all the gains from several times getting it right. So I use the credit card anyway and pay it off every month - that payoff is the one number I can get right every month.