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Hi Ejovi, If it were my site, I wouldn't do this. I've seen it done on plenty of sites, but at best I don't believe it provides a good user experience, and at worst you might put yourself at risk of a panda update. If it were me, at the very least I would be writing a paragraph or two about why you're sharing the content with your visitors, and then proceed to quote and link to the original. This should avoid any issues since you're adding unique content to the page. In addition to adding at least a paragraph or two of unique content, I would also try and change the title of the page from what the original post was titled. If you're looking to partially automate this process in Wordpress, you could use a RSS -> draft post plugin of some kind, and then manually add content to each draft post as it comes in. The more you can add, the less likely it is to be viewed as duplicate or thin content. One final disclaimer - in theory this content won't perform as well for more competitive keywords. You'll usually get better results from the original content that you're producing. If your goal is to produce content that's going to perform well in search, you're better off sticking with mostly original content.

Ideally I would use the /market/ directory over a sub directory.  That would allow the store to benefit from the authority of the existing site, rather than starting afresh on a new sub-domain. Some software combinations could make that tricky, but in most cases it should be fine.  If it does get tricky there is also a work around where you can have content on a subdomain served from a directly url using a reverse proxy.  Messy though. The final option seems unnecessarily complicated to me.  I'm not sure what you are trying to achieve there.