It probably varies from state-to-state but here in IL, an ID costs $20 for adults, $10 for minors, and is free to the disabled. And its valid for 8 years. I suppose we can create another program for those adults that cant absorb the $2.50 annual average cost.
One other issue may be problems with supporting documentation for ID in some states. Don't think anyone'll actually take a honest look at it, though, which is a shame.