It's an eCommerce coin mall. Granted the prices are not great but with ebay being flooded with counterfeits - the onus comes down to the buyer. Thankfully there are still honest sellers elsewhere.
It's like VCoins. But in Europe. Actually some of the sellers use both platforms, plus eBay. Basically it's individual storefronts lumped in one searchable place. You have to check the specific seller regarding selling terms, payment, shipping, returns, etc. No different than buying from any internet based vendor, numismatics or otherwise. Depends on your comfort level there. If you have a specific vendor you'd like feedback on, post who it is (or try the worldwide subforum to get to folks who generally buy more widely). There are some I've bought from, though usually through VCoins.
That's what ebay was in the beginning as well. They were "just a venue", caveat emptor, and if you had any problems try and work it out between yourselves because ebay took no position in the matter. I've purchased on Ma-Shops a few times, and can't say I've been disappointed. Maybe for common stuff that is readily available elsewhere the Ma-Shops prices may be high, but is you can't find it elsewhere you pays the money or does without.
