In absolute terms, if these tools are useful to you then you most likely make enough that $25 is an inconsequential amount of money.
But relatively speaking, with 1) no way to preview functionality; 2) no way to preview code for quality; 3) the inability to get a full refund if they turn out to be garbage; 4) having to download executable instead of just running them in a browser (even though they're apparently written as web apps); and, 5) not having any idea who this person is, it's a big ask.
It’s a bunch of stuff you can get for free and web based by googling. It’s probably more convenient for me to use the free ones because I can the have a list of bookmarks to the things I use. Also there are free dev tools out there I might need that are not in this kit, so I’d need that anyway.
1. Generating fake testimonials, even if you're honest about (albeit with greyed out small text), is pretty scummy.
2. Not having a no-questions-asked 100% refund option is a non-starter for many people, myself included.
3. $25 is a lot to ask for unproven executables from an unknown developer with no refund available.
4. Written in technology I've never heard of (maybe others have though).
5. No links to any of your social platforms.
6. No comment or info here from the author in over a day on an HN account with no comment activity in 6 months.