Account manager and support contract are sold together... $150,000/yr paid up front + 4% of yearly spend.
Seems insanely high, especially compared to the next step down which is only $250/mo per user... you could get by with a separate account with a single master user that controlled all the deployments and billing and only pay $3,000/yr. What you get for that extra $147,000+/year is that you talk directly with the lowest level engineer actually working on the problem rather than relaying messages that lose context... but you'll still need to know what you're talking about and be able to actually help the engineer rather than spin them in circles, or you'll be kept at bay.
For consumers, https://one.google.com/about/support is the way to pay for the support, since they claim "Cross-Google" support. I haven't used Google One support (even though I am a member as I have a subscription to their storage plan), so I don't know how good it is though, and it's not super clear how "cross" it really is. https://one.google.com/support says 2-3 min response for phone/chat though.
Last time I filed one of those P1 tickets, it was assigned to someone immediately but we didn't get any useful help from the support people for 7 hours.
It took multiple escalations to people responsible for the specific service and the issue was entirely Google's service having an error. Meanwhile production was hard-down that whole time.
So the reason I would want guaranteed human support from Google is in the event they mistakenly ban my account of 13 years. If it also bans me from the support product then it’s completely pointless.