You're right; you need additional valid posts before you can post in Buy & Sell.

However, trying to find out if someone else has one is not the only way to find out how to get a replacement. Someone might know of another source, or how to work through a vendor's customer service system.

I might suggest trying light gear first - it's a more active forum (based on number of posts), so you might be more likely to have someone respond.

What kind of pot lid are you looking for?