Consultants in this field tend to be far MORE expensive than FTEs, even the independent types, though major companies are trying to coax Congress into expanding H1-B visa quotas in the hopes of changing that. Supply and demand. In my experience, consultants are brought in when there's a major skill set missing in house, and/or a major project that requires more workforce than normal. Not that there aren't shops out there who try to keep everyone on contract and outsource whenever possible... they're just not the ones I'm going to choose to work for.

As for becoming an independent consultant with your former employer... I've actually seen that work out well to the benefit of both employer and employee. The key word there is "retirement."