In my experience, the Indian contractors are going to be lower rated technically, but for 1/4 the price you can question whether you NEED someone who's a 4/5 or whether you can get by with a 2 or 3.

Determining what functions need top technical people is something most managers figure out after offshoring, when the damage is already done.

Contractors are incredibly valuable in certain respects, but one thing they don't do generally is write code for future maintainability... they're under a lot of pressure to produce workable results quickly, which opposes planning for the long term technically speaking.

Like offshoring itself, that may not matter depending on the company and what it does.