Phoenix NP is a layered offer, not a single monthly number
The first thing to understand is that Phoenix NP has at least two cost layers in the tracked public data. There is a provider-side service plan at $99.99 every 4 weeks, and there are separate medication references including Foundayo at $299 and Zepbound at $449.
That means the low headline number is only part of the story. If you want a fair comparison against more all-in offers, you need to treat the provider fee and the medication rows separately.