NYSDOT only gives GMAW short circuiting certifications to minor miscellaneous shops such as for ornamental bridge work. Sometimes they give it to sign shops. The certification is useless any where else. The WPQR is difficult to duplicate, and cannot be transferred. This particular certification is not considered to be significant in the grand scheme of welding. If you are not qualified in other processes, your certification does little to recommend you for other work, or other employers. If you are in the central NJ area, you can probably expect $15 to 17$ per hour. If you are in a Union Shop, or can get in a Union shop (Sheet Metal Workers Union), you could get considerably more, $25 to 30$ per hour plus benefits, AFTER SUCCESSFULLY COMPLETING APPRENTICESHIP. (5 years)
I know you wanted to hear something rosier, but that is reality as I know it.