Or we could benefit by having a permanent team who will be cheaper in the long-run, because of familiarity with the systems and projects they build and maintain.

Hiring outside consultants of any kind for a permanent government requirement is pure insanity (or in reality, grift) if you ask me.

I'm sure there are consultancies who do a great job. The actual employees are usually not the problem.

But let's just give those same employees a permanent job and cut out the middle men who are offering no value whatsoever.