AdobePortfolio comes with the CreativeCloud suite at $53 / month, or separate at $10/month
The main thing AdobePortfolio has going for it is that you also get access to Photoshop CC and Lightroom CC, plus 20GB storage. Oh, and a bunch of fonts from Typekit, another Adobe product. That's why lots of photographers already have an account to AdobePortfolio but never use it.
The functionality of the actual portfolio builder is very basic and there's no ecommerce available.
If you're already a CreativeCloud subscriber, give it a shot, you're already paying for it :)
