[tzs]

I was curious how it compared to a credit card, since if you wanted a 4 payment over 6 week plan you could simply use a credit card and make an immediate payment of 1/4th to your card, and then 3 more payments of that amount over the next 6 weeks.

A quick internet search says that the average US credit card currently has an interest rate of 16%.

Paying off your credit card on the aforementioned schedule at that interest rate, assuming a monthly billing cycle that starts right before your purchase, you'll pay under $4 in interest if the purchase was under $487. If the purchase is over that, Zip is cheaper.

If your purchase comes in the middle of a billing cycle, the breakeven is $811.

(Both of those are assuming that you have nothing else on that card, so that the billing cycle in which you pay off the 4th payment will end with a 0 balance, and so there will be no interest for that cycle).

(Also I'm assuming you aren't using a rewards card. I'm using a card with 5% cash back on online purchases, making it quite a bit harder for Zip to beat the card).