I'm not a welder but when I was in the navy back in the day welders certified to weld on submarines made some serious money.
But not to be negative I am a mechanic and it does take a serious toll on your body. I tell young guys to look into electrian, HVAC or a trade requiring a license. This helps keep illegals from undercutting you.
A lot of cheap asses will take their car to a shade tree and I make it a point to charge the crap out of them when they have to bring it to me afterwards.