As you may or may not know, I have worked in the Dental field for almost 7 years.
The problems you experienced with anesthetic are common and can be avoided by telling the dentist to use "non-epi" injections. The numbness does not last as long, but if you get rapid heart-beats, your dentist should be more than happy to use an alternative.
I know I'm prejudiced, but it always makes me roll my eyes when someone says, "I didn't go see a dentist for 10 years and now I need 6 root canals." If you keep up with regular visits, chances are most expensive restorations can be avoided and decay can be arrested before it gets into the nerve chamber.
Also, dentists generally do not seek to "rip off" people with dental insurance. In fact, we prefer to treat people without insurance because you don't have the insurance company dictating what procedures we can and cannot do. If a patient happens to have a generous insurance plan, we may suggest they get necessary dental work done to prevent future complications or emergencies.
If you dent your fender and take your car into several body shops for an estimate, you may find quite a difference in price to fix the dent. One place may be very cheap, but what they will do is fill the dent with putty and paint over it with a color that doesn't quite match.
Dentistry can be the same way. There may be a cheap way and expensive way to "fix" a tooth, but usually the cheap method won't last, doesn't look good, and may require a more expensive solution in a short time.
We are doing everything we possibly can to get people to stop hating dental visits. We use aroma-therapy, massage chairs, and spa-type atmosphere to make people feel relaxed and happy. Most people leave my office saying they didn't realize how pleasant a trip to the dentist could be. We are always pleased when our patients brag to their friends and neighbors about how "gentle" their dentist is.
Please write to me if you want a recommendation of a dentist in your area.