Nope. Point by point, I have a few comments:

> Two guaranteed responses: (1) confirmation your application is received, and (2) if/when you are no longer a candidate for the job.

This should be common decency.

> Responses might be automated emails from “no reply” addresses.

So I'm paying to apply for a job, and not even guaranteed human contact?

> At least half of the $5 application fee goes to a charity

There's something cringy about this. Something along the lines of knowing that someone is profiting from this, but at the same time they don't want to seem like they're profiting on your unemployment and desperation, so they go for the textbook "oh, (some of) this money will be donated to some charity", treating the "charity" as just a generic economic/marketing tool.

> Even this small fee will cause many job seekers to opt themselves out of applying for jobs they aren’t qualified for, resulting in much fewer unqualified applications for HR to deal with (huge time savings).

Say this is hypothetically in place. You effectively transferring some of the cost of HR from the company to the applicants, now that companies can have smaller HR departments. But who has the upper hand here? Companies that suffer from this "too many applicants" problem aren't your small mom-and-pop shops; they are the big players, everyone wants to work for. It makes sense to assume then that these companies have the resources to hire bigger HR departments and solve their issue. Applicants, they are seeking for job because they NEED a job; morally, doesn't it make sense that the important company takes on the toll of this issue, its recruitment issue, instead of the applicants?

Now, lets think about the applicants. What I see this doing; take two people with the exact same qualifications.

The first one, applicant A, is well-off, will buy himself a better recruiting experience. He will throw his resume everywhere, apply 50 times, cause $250 is like pocket change. In a bigger pool there could well be more hits, so potentially more offers, which not only increases confidence and reduces stress, but also gives the applicant leverage to get even more and better subsequent offers.

The second one, applicant B, has the same qualifications but is not as well off; he thinks twice before throwing each hook. He wants to keep it under $100, so 20 applications theoretically would yield half or less than half the offers applicant A got. This translates to more stress, for there are fewer backup options, less confidence which could yield to even less offers, and much less leverage to get more or better offers.

Is this fair? It just makes the process harder inversely proportional to how big of a deal $5 is to you, and the difficulty of the application process can translate into differing results, even if both applicants have the same qualifications.

Hold that thought, and lets explore another comment I have to make. This one is a bit more speculative, but its worth mentioning too. If none of the money is going to the company, but only half is going to charity, it must be because theres an intermediary who is organizing this whole operation in behalf of the company. This intermediary is arguably another company, a startup, and as it tends to be with things here, for profit.

It needs to grow, so what stops it from changing the $5 tag? What if it's a really desired company we're talking about? Why not $10 or $15? In fact, why a flat rate and not some sort of auction? Surge pricing and all?

Now, go back to that thought you were holding. The unfairness only gets worse as this intermediary becomes more profitable. Suddenly one applicant can still do 50 applications, but the other one is stuck with even fewer shots. Same qualifications, very different opportunities.

Lastly, a closing remark. This is an interesting idea, but it sounds too much like companies selling the opportunity to work for them, which IMO, is just not a good notion. And there's a solution at hand already. As I mentioned before, one can assume that companies have the upper hand and those suffering from this issue have the resources to fix it. If recruiters are suffering at all today, it's because companies would rather save a buck and have an understaffed HR department, or are dumb and overly zealous with their recruitment and spreading the net wider than they can handle.