Legitimate marketplace scripts receive regular updates to patch security vulnerabilities. A nulled script is a "snapshot" in time. If a critical SQL injection vulnerability is discovered in the original script, the developer will issue a patch. However, your nulled script cannot be updated (or updating it will break the null/crack). Your site becomes a sitting duck for automated bot attacks.
While the allure of a nulled script may seem tempting, it's essential to consider the legitimate alternatives:
A successful marketplace needs to be stable. Nulled scripts are inherently unstable.