In my opinion, such generalisations such as the one quoted above, made in the McWilliams article, are not very accurate. Firstly, in all my research into property-related matters in Hungary, the existence of a price for the Irish isn't a common occurance. There are maybe one or two unscrupulous companies, who have been documented in the Irish media, but that's it as far as I can see. Also yields aren't 'perilously low' in Budapest. With a good investment, they are about 6-7%. Claiming that 'Paddy feels he has a bargain' makes Irish investors appear naive, when in reality, my experience has been that many investors from other countries have been closely watching in which countries the Irish euro is invested in.
In relation to the Polish market, I'd imagine that if estate agents over there want to keep their reputations, they will not try to rip people off either. It doesn't make economic sense to do so.