For anyone out there in the same spot, I'll say that I switched my last company to Atlassian's OpsGenie and it was a 10x cost savings for the same feature set.
If cost is the only measure: I understand. But time lost in various areas of the software package (performance alone! Before we get into weird UX paradigms and esoteric query languages, shoddy search systems etc;) surely has an impact on cost. Having your employees spending a lot of time navigating janky software has a cost too.
I'm generally not a fan of Atlassian anything, but Opsgenie was really good before Atlassian purchased them and they're still really good.
On the flip side in the 8ish months I used Opsgenie I saw a litany of issues, like the mobile app silently logging people out (and thus not delivering push notifications) and the app failing to send SMS notifications. We had pages get dropped by the primary because they never got a notification.
I want exactly one feature from my pager, delivering 100% of my pages. It's not a situation where I'm ok with 99% success rate, and that seemed to be the tradeoff and what you are paying for with Pagerduty.