Esra, sometimes the packages dont make it across borders ya know (siezed by police/customs, or a greedy postal worker). Seeing as he does good business with hundreds of other people, I find it hard to believe that he scammed your friends.
And anyway, Belgium is next to Holland, is it not? Why didnt they just take a weekend break when they got some time off work? Woulda worked out the same price probably - could have even slept in the car, instead of renting an apartment for a few days. We all know that after a few bowls of good indica that everywhere seems a comfy place to sleep!