How to make your first sale at agon

First of all, I apologize if this post is in the wrong topic, but I thought that since I'm trying to sell an amp this might be the right place to post. Will be happy to move it to a different topic if needed.

So I have been a (relatively) active forum user for a number of years, but have only bought maybe 2 or 3 items here. Never sold anything. Usually, when I'm looking at the items for sale here I always review the seller's information, specifically how many items he or she has sold in the last 12 months or longer. If that number is zero, I generally ignore due to the high-risk factor.

Ironically, I am now finding myself on the other side of the equation :)
I have a Parasound A21 amplifier in pristine condition that I want to sell since I've decided to buy an integrated amp. But I have no idea how to post my first ad on agon and provide some sort of comfort that, despite the lack of any track record as a seller, I am a legitimate seller and will stand behind any transaction.

How did you guys make your first sale? Any advice is greatly appreciated.