My theory as to why Edison wages are so low: most of the Edison companies are low end bodyshops - if you need a warm body with J2EE, they will give you a warm body. Their competitive advantage is that the Edison guys they hire never talk to non-Indians [1] and never discover they are ridiculously underpaid.
Incidentally, the food in Edison is fantastic. Jersey City also has good low end food (e.g., dosas), though nothing great at the higher end.
[1] It's not even an Indian nationalism thing - many of them avoid socializing with Indians from a different state/ethnicity. I get dirty looks when they see me with an Indian girl.