My main feedback is that I don't know which step to take next. I see 6 links in the yellow bar ... be a little more deliberate/forceful in directing me on what to do next.
Not that you asked, but here's some wacky/random ideas off the top of my head:
- Do Stripe checkout in addition to PayPal (ask for Stripe API key & secret over SSL)
- Provision a Twilio phone number for each list after registration. Use it as a temporary way for sellers to call the buyer, for notifications, and to add/remove items via SMS
- For quick mobile integration, use MailGun to post incoming email messages to your app and turn them into listings. That way people can add items & pictures from their smartphone. I've done this and you can literally get it going in < 1 hour.
- Allow me to sell a digital file. If I add a [d] to a line item in my list, prompt me to upload a .zip file or high-res JPG. BOOM, instant store for selling stock photography, ebooks, or WordPress themes.