Are local private tour guides expensive?

Can one really put a price on gaining insight and a unique experience when they travel to a new country?
If you can get a local private tour guide for less than 10USD per hour is most exotic countries like Peru, Bolivia, Cambodia, Kenya is that not a bargain?

Personally, I have learnt so much from my interaction with private tour guides while travelling overseas that I now view it as a basic need. The personal contact and unique experience are priceless.

Have an adventure!

Dave C