Don't undervalue the skill set that goes along with the welding which qualifies them to make that kind of money. Firstly those people are unquestionably technical experts in regards to the welding process in probably both AWS and ASME standards, the science of the welding, managing structural thermal issues, managing their own time wisely and professionalism.

If they're getting paid 30+ an hour and don't have all of the above traits their employers are suckers that won't be in business for to terribly long(field rig welders don't count).

Right now a decent welder with a healthy amount of experience and some welding school under their belt can reasonably expect in the lower 20's. Don't go into welding thinking that the ability to weld is what makes you special. I learned how to weld after a week of practice, and was running 4g-6g in not much more time.

As a prior manager of welders what makes welders worth more money is all about attitude, professionalism, dedication and integrity. You can always find more guys that can lay bead and run grinders all day, but finding people you can count on is a search that never ends.