I just read AndyKelley's comment you mentioned, and I can't find anything wrong with it; it's not even saying anything negative about Rust. It just observes that Rust spends more.

Is $100k/year a good salary? Depends. For a software engineer, no, since most software engineers make more. For a paramedic, yes, since most paramedics make less.

To know if $15k is a lot to spend on CI and a website, a great way to answer that question is to look at what peers spend on the same thing. Hard to think of many better peer comparisons for Zig than Rust.