This is a bit of an old chestnut, or would that be a hazelnut, why is it that it would appear only to be the Brits or I guess other foreigners who get ripped off?  Why don't any of the locals get ripped off?  Are the estate agents just biased?  They hate foreigners especially? 
I would suggest not, an estate would rip anyone off given the chance if they are that sort of agent.  No, I would tend to think that it might have something to do with the fact that when people come over here they tend to leave their common sense behind.  In the Uk who would EVER buy a property without searches, lawyers, or just by trusting the word of a local estate agent? 
There are sharks everywhere but fools as well.

I honestly don`t think anyone here is more dishonest than anyone else elsewhere.