The average driveway costs around $5k and the average home cost in the USA is now $416. So while it could be possible to shave off half of that 1.2% cost and save 0.6% it would come with needing some kind of easement or shared arrangement with your neighbor (who could change and who you may or may not be on good terms with). You also couldn't leave your vehicle or a visiting vehicle in the middle of the driveway since you'd be blocking someone else.

I had a shared driveway with my neighbor in Michigan for many years. It worked out well, especially for more efficient optimized snow shoveling. But I wouldn't say it was some kind of game changer and cure to America's housing ills.

I'm not sure about that price that. You'd pay that and more for cement (or ready concrete) itself.

Quick google says $200 NZD per square meter. My driveway is at least 200sqm, thats 40k...