I have heard thousands of times Spaniards talking about the “stupid foreigners” which were paying 30-50% above market (or more). This created a lot of damage, and transformed many Spaniards in corrupt people willing to sell anything to “stupid foreigners”.
Unlike, today in the olden days there were no prices displayed in the shop windows. In fact most estate agents if you want to call them estate were farmers or people hanging around in the bars. This lack of transparency allowed the local charging the stupid foreginors a different price.
The, property market in London is always under pressure from foreginors buying. The prices are stated at the estate agents & its the same for the locals or the foreginors. For historical prices, anybody can look at the land registry, records to see what the properties were sold for. This cannot be done in Spain due to under declaration etc.
It should not be overlooked that in UK, foreigners do not pay capital gains tax as a non residents. However the non resident pays capital gains tax in Spain and until recently at a higher percentage rate.
Clearly, ripping off the stupid foreigner is very much part of Spain at all levels. Its not Taxi drivers of Malaga airport.