Overcharges on second hand cars by almost double ?

I went to your imperial select roodepoort and dealt with Johan du Plooy in search of an Auto for around R65000..... today however Johan tried to sell me a Atos 1.1 Auto with low km 2007 model for R78000... cliamed this to be the best price but both online i seem a same spec car for R50000 and my insruance tesll me retail is 40000 but if car is in good condition and low km then it would sell for no more than 50000.... also a new Aot 2005 sold for R75000... so how on earth do you sell a older car for R78000 and not call this a *******?!! and then when we talk to Johan he gets all rude and sarcastic and says good luck to my complaint!! nice!!