Besides getting fired, what are some consequences of working with an expired DACA

Asking for.... a friend.

I see you're no longer concerned about paying the money for a shorter term EAD, huh? LOL

Paying off my car instead. I’ll be done in 3 months instead of 3 years.

Well it is illegal but it depends on where you work. Some smaller companies never ask for an EAD again. I worked at a small company and they never asked me for my EAD again even after it had expired. I had gotten it renewed but they never asked for it so I didn’t mention it or anything. If they would have asked about it, I had the new one already so I just left it at that.

If you want to read up further:
https://www.immi-usa.com/uscis-unauthorized-employment/

Companies will get letters from the gov if your ead expire and you keep working.

You accrue unlawful presence time while it’s expired

It depends on how the EAD was acquired, or in short its category. Some categories allow one to have automatic extensions. The following categories are allowed. Unforunately, C33 is NOT one of them.

That is illegal. If you do that it could come back to haunt you when you're filing for Green Card. You can't work without work authorization.

A one time payment of $500 is going to pay off your car from 3 years to 3 months?

That is dead on arrival.