How would relinquishing that help, is access to land a real issue? You can probably already buy a lot for cheap right now, but it will be far from urban centers and won't be habitable without a ton of investment. Would have zero effect on housing.
And if it is a tension slab, you absolutely cannot cut into it.
- Autos - Airlines - Banks - Farming
They all require massive injections of liquidity for the purpose of subsidizing poor stewardship. "Costs" is not a feasible excuse for continued economic oppression.
Initial investment in locality based infrastructure creates the market; expansion through time with connected systems, if so desired, would then be an increased capital cost over time, not an upfront requirement. We can generate competition in building whole new cities, like corporations are attempting to do today, which can help stabilize and reduce the growing costs of rent and housing in major metropolitan areas. It absolutely would have an impact - just not when you construct a fallacious form for it to exist in as a failure by design; which is most of commercial and residential real estate given zoning requirements and the massive middle-man industry surrounding it.
The reason it's cheap is that no one wants to develop it.