How to become trustworthy enough to buy from?

I'm new here, and would like to sell something.

The only problem being that it's a steam account, so it's a higher value item I suppose

What would it take for someone like me to sell this item? I'm not much into selling/trading things online, so I have no real way of building up rep through sales.

Are there other characteristics people look out for such as Paypal verification for instance? I had to go through a similar ordeal on another site where I wanted to sell an unusual hat in TF2, and had zero rep there as well, but with a trusted middleman, and my verified Paypal account, the transaction went ok.