I noticed the Buy Now Pay Later deal seems to state that the interest is "deferred". If the balance isn't paid off that deferred interest becomes payable.
So, I buy a £1,000 telly and apply for a store card. I don't know how many reminders Argos send but suppose I just forget to pay on time and I'm a couple of days late. I'd then owe Argos £1,259? Seems rather shocking to me.