That sounds like bad parenting. Kid wants skin? Fine, make them understand the value of it and work for it though. Teach them that buying an overpriced skin will cost them eg. 10 hours of actual work - like chores.
The problem isn't virtual items, everyone pays money for non material experiences/services - and on a long enough timescale even material things wear down/break.
The important thing to teach a kid is if the value they derive from buy a skin eg. and whatever it brings to them (happiness, bragging rights) is more important that opportunity cost of paying for that.
If the cost is always zero (daddy pays) - then the kid will not stop to think about it ever.
Something about telling a kid that the iron is hot vs the kid needing to burn himself to learn.