Just speaking from my experience -- if the company is a big corp, usually the wages follow average market rates (I was paid market average wage in a top advertising corp in the world and I got my green card there in 6-7 years). Bureau of Labor Statistics puts out average market rates for each job category and the H1B sponsor has to match or pay above that to get the H1B application approved. I was also checking out my market rates (i.e., applying for other companies that allows H1B transfer) constantly during my H1B time because I can move to another job if my current company was paying me lower than average wages.
On the other hand, for some shady companies that are set up as contract shops, then I'd not be surprised if the wages are lower than average market rate, but I have never worked at one, so I might be misleading by even mentioning this here.
On the other hand, for some shady companies that are set up as contract shops, then I'd not be surprised if the wages are lower than average market rate, but I have never worked at one, so I might be misleading by even mentioning this here.