Something like these healthcare exchanges should have been put to the market in a from where the revenue is directly tied to the end goal: The successful purchase of health insurance by customers (or whatever is the case here, I'm not intimately familiar with the mechanics). Have providers bid on the full thing by revenue pr. successful transaction + an SLA that deducts an appropriate penalty if it isn't met.
Ideally, you don't even need to pick a winner, you can just say that any provider that successfully operates such a marketplace will get the revenue per transaction and let the market sort it out. End users will gravitate towards the sites that are fast and easy to use, "Consumer Reports" will test them etc. Lean, agile shops will win. Clunky, well-connected, but technically unsophisticated government contractors will fail.