Dental hygienist a good job?

Remuneration varies with location, time and other factors. If you feel driven to root-around nin other people's mouths - go for it.

The figures you have may be correct. Keep in mind that many DH's are independent contractors and don't get paid for time between jobs or when they don't have enough work to fill their time. There is no advancement. You can't work your way to being a dentist :-) As an independent contractor you would not have benefits like paid vacation and health insurance. All that said I think it is a good field to go into as long as you are aware of the limitations.