Is there anything worth justifying
$600/year to a company that can barely
The question is, what will be the cost to your company of the mysql server fails in some obscure way. Will you be able to afford some down-time to restore a copy of your database if it was corrupt for some reason?
If you are running a shopping site, and if the mysql server goes down, the outage will cost you in lost sales. If those lost sales are more then the cost of the enterprise license then not buying the license would be a bad decision.
If this is for a site small blog or something and mysql goes down, you may just annoy a few of your visitors.
You need to decide what your level of risk is, and if you need to pay for professional support to help you minimize that risk.
Keep in mind that when/if you have a critical failure you probably can find someone who will help you, it will just cost you more then if you had gotten a support contract ahead of time.
You may want to at least make sure you a phone number written down of someone you can call in a emergency. There are probably mysql experts that you can hire in a pinch.