We have a few "price categories" here. They start with rock bottom €1.50 for a single Schuko socket. The quality of those is usually that poor that I refuse to connect them.
The next group is around €4, no well-known brand names yet but ok to work with. We wired out whole place with switches and sockets out of that price range in 2002 and none of them failed yet. Big brands like Berker, Legrand and Busch-Jaeger start around €7 and go up to more than €10 for some. These are what you'd likely get if an EC wired your home. Then there are the luxury series that can get real expensive - €70 for a fake marble and brass socket for example. That's a design issue, not quality.
BS stuff tends to be a lot sturdier, even the cheapest. I recently saw double sockets that sold for around 2 pounds each and look pretty reliable. Much better than stuff in that price range here, where tightening the terminal screws most likely destroys the whole socket body.
Alan, with the strong ground scrapers Schuko plugs usually beg to be slammed into the socket too
