I'am one of the authors of bda.plone.shop and its ecosystem. Robert Niederreiter is lead of the project and @agitator, @thet and me are involved in depth. We also got already awesome contributions from the community. We never advertised it a lot and used it primary for our own projects, but its opensource with an open contribution model. So some like @espenmn @ezvirtual and others found it and used it!
bda.plone.shop is a micro-framework for shops. Its was made with the experience of PloneShop (Plone 1.0) PloneMall (Plone 2.0-3.x) and some minor special projects we're developed by us (BlueDynamics Alliance).
bda.plone.shop is very flexible and comes with a first out-of-the-box experience. But in fact it's meant to be extended with an own package for configuration, maybe own types, custom payments and all you need. Also we're very open for discussions and contributions to its core packages.
We're using it in very different projects. There is also bda.plone.ticketshop based on bda.plone.shop.
At the moment its not tested on Plone 5. From it's architecture I'am sure its not a big deal to make it work. It supports dexterity very well. All around new Resource Registries may need some love. We try so find some time at Plone conference to make it work with Plone 5.