Is it common for a broker to ask a $500 fee in case we back off the offer?

[Eyal Goren]

We're about to sign an offer. We're seeing an unfamiliar clause and wanted to verify that we're not making a mistake.

The broker asks for a $500 fee (they say they reserve the right to retain/charge in its discretion, in any non-closing event to cover for its services).

Is it common for a broker to ask a $500 fee out of the EMD in case we back off the offer?

**I understand the need for a fee for all the hard work they're doing - but prefer to have strict numbers and processes