Yes, some companies do pay more than others. In the summer of 1981 when Detroit was flooded with work, I could make $50/hr no problem for contract work. That was on top of a 56 hour work week. In 1999 in Detroit, the average unburdened wage for an experienced designer was between $25/$35 an hour.
The problem is, all those jobs are gone and they're not coming back. I, like a lot of people I know, have relocated. We recently arrived in Sacramento and I've just started looking. I have thirty years experience as a designer.
The work in Detroit disappeared for a variety of reasons: declining market share, soft tooling and offshoring. 300,000 jobs lost in SE MI in the last five years. That's the trickle down economy for you.
I'm ten years from retirement, I don't know if I'd recommend a young person to even enter the field.
A lot of guys in Detroit, for their last job, were training Eastern europeans and Indians in UG, Catia and tool design. In India, they're working for $100/wk and living in dormatories. How you gonna compete with that.
My only regret is I wish I were closer to retirement.