There’s a difference between a prostitute and a golddigger. Going by the situation your described, your friend’s GF would be a golddigger…not a prostitute. Now IF your friend gave her those gifts and expected sexual favors in return b/c of those gifts and got it…then she would be a prostitute.
There are many girls out there who date guys for money or gifts. But that doesn’t mean that every single girl is dating her BF for money or gifts.
Its just like men who marry a girl for looks…many men out there marry girls as “trophy wives”. But that doesn’t mean every single man out there picked his wife only b/c of her looks.
You can’t lump all “GFs” into one category.