I haven't dealt with IBM, but I have been in charge of outsourcing before. Early on we used Indians, but it became expensive so we moved on to the Philippines. Both had the issue you're describing. If you found someone good they would be gone in a few months for more money. I remember arguing with management above me because I wanted to pay a person 40k instead of 35k (I think those were the numbers, it's been awhile) because he was good, and communicated well (another issue). I was overruled and as soon as this person became proficient, and presumably found a better paying job he never showed up again.

Eventually I convinced management that even if we had to pay 2-3x for a competent developer stateside, it was worth the money because of the hidden costs of trying to outsource. The work we were doing required someone to be invested in learning the business and the problems we were trying to solve.