If I've stumbled across what I think is a security issue in your systems, there is zero chance that I'm going to get out my credit card and pay you for the privilege of responsibly disclosing it to you. Especially if it's the vulnerability is in the site hosting the contact form.
I don’t participate in bounties at all unless I believe there is a moral obligation or I’m set to make thousands of dollars. In each case, $0.05 is fine.
For a typical commercial entity? $0.05 is not a deterrent; the companies legal team is and has been for a decade.
In most cases I'd think it's more of a deterrent for commercial entities, because spending money create complexity. Most employees are not in a position to just directly spend their organisation's money, so that $0.05 will often mean needing to get approval, purchase orders, deciding which cost centre it comes from, needing an invoice, etc, etc.
Very few people are going to invest that much effort when they're trying to do the company that they're reporting to a favour.
