25% sounds a touch high to me, certainly for normal engineering role in tech (though I could well imagine it being more for niche or very senior roles)

12.5-20% was the typical range when I last dealt with them in the mid-late 2010s (usually varying with the seniority of the role). Perhaps things have changed to reflect the additional value they provide in bypassing the torrent of spam that's currently plaguing the recruitment process - but 25% still feels higher than I'd expect.

I agree that you can use this as an argument when negotiating a signing bonus if you're a direct candidate. Won't always work because the hiring manager usually isn't the person who's deciding whether or not to use a recruiter/headhunter (and their fee probably comes from a separate budget), but it's worth a try. I did exactly that when last changing jobs, and managed to get an additional 10%.

You can probably negotiate the fee, that seems high.

On the candidate side, job hunting is completely broken. Are you sure this person’s resume would have been seen by a real person if they applied through the job portal?

> As the person doing the hiring that kind of incentives me to strive for a lower salary, at least for that first year

That's a very bad way to look at it. If you think recruiters are too expensive don't use them, but I suspect it makes no difference to you as hiring manager as that was previously approved and budgeted, and low-balling a candidate is not the best way to start a relationship or to attract the best.