I’ll ask for something preventative or that otherwise hardens our systems. They ask “is it a need?” and I’ll say something like “we can function without, but that means we have a 5-10% chance in the next 6mo of having a major failure and embarrassing ourselves in front of a live audience in the thousands as well as our client.” They then decide how much that risk is worth to them, and whatever they decide is kind of out of my hands at that point. If the thing I warned them of comes because they didn’t pay for it, I can point to the receipts (though I’ve never had to, we’re small enough people remember those conversations).
60% of the time they just get what I need maybe? But ultimately it’s about CYA. Tell them what’s up, tell them what the solution is, tell them what the consequences are if they don’t do the solution, and make them decide.
Again this obviously depends on company culture and structure, but I can’t imagine on the only person who can do this!