Did you even look at your link? Looking at [1] only two H1B employees received a wage offer of less than 103k, and in 2013 only one (Database administrator) received under 100k. In every single case the prevailing wage on the application was lower than the wage offer.
[1] http://visadoor.com/h1bvisa-by-companies-2014-yourpeople#.VH...
http://visadoor.com/h1bvisa-2014-I-200-14065-134617/software...
Making $70k in some midwestern city will get you a better house, better access to education for your children, and generally better quality of life than what $200k will get you in the Valley. I know people who've lived in both worlds tell me exactly this.
So, having offers at 30-50% is not a good thing, it's a bad thing. It should be much higher than that.