Normally the $89 per month plan is actually $99, so there's a $10 discount on that plan as well.
There's also a phone trade-in deal where you get 30% off via JB coupon, in addition to the trade-in credit you'd normally get. But this is only good for buying Samsung S22 phones. Here's a screenshot of the trade-in deal https://imgur.com/a/bioWsUi
Maybe worth combining the two?
24 is too long… give me 12