Since most software development teams charge on a time and materials basis, let’s compare the hourly rates of RoR consultants worldwide. Thus, the average salary of a Ruby on Rails consultant in the USA varies between $80–150 per hour, depending on the state and the consultant’s working experience. On the other hand, if you’re looking in the UK, the rates for Ruby on Rails consulting there fall between $60–100 per hour.
In Europe, you can hire a consultant for $40–70 per hour of work. At that, specialists in Eastern Europe (Poland, Romania, Slovakia, Ukraine, the Czech Republic, and Hungary) tend to charge on the lower side of the range.
Such a difference is caused by the price of living in those countries. Yet, there is no evidence of significant differences in skill levels among developers from all those countries. So, if you outsource IT services, the price can be your deciding factor.