IBM has the resources and infrastructure others firms don't have. It can afford to pay higher rates for the top IT people and it has the software and management and the backup in the US to ensure that projects are performed properly.
But as a rule, Poland, India, ...other cheaper locales don't offer the quality of the US, Israel, ....look to the places where the world's top software/computer chip design/hardware is being designed and built. There is a correlation.
For example, Israel has a population of only 8 million yet creates more original software and startups (purchased by developed nations) than all of India. India buys hi-tech military technology from Israel (and the US).