I'm spreaking from a UK perspective (Region 2) but cost depends on the machine. Some are fairly cheap ( Pioneer 505 springs to mind ) because it just involves shorting out a circuit inside the machine - others require special chips to be soldered in. There are a few in the UK which can be switched by using an engineering code via the remote control. On thing to watch out for is that European discs are encoded using different TV formats and unless either a) your TV supports these formats or b) the DVD player switches formats, you won't be able to watch the films.