The thing to keep in mind is that there exist things which have “circumstantial value”, meaning that the usefulness of something depends on the beholder’s circumstances at some point in time. Such an object can actually have multiple valuations, as compared to goods (which have a single, calculable market value) or sentimental objects (“priceless” to their owner).
To use an easy example, consider a sportsball ticket. Presenting it at the ballfield is redeemable for a seat to watch the game at the time and place written on the ticket. And it can be transferred – despite Ticketmaster’s best efforts – so someone else could enjoy the same. But if the ticket is unused and the game is over, then the ticket is now worthless. Or if the ticket holder doesn’t enjoy watching sportsball, their valuation of the ticket is near nil.
So to start, the coupon book is arguable “worth” $30, $0, or somewhere in between. Not everyone will use every coupon in the book. But if using just one coupon will result in a savings of at least $1, then perhaps the holder would see net-value from that deal. In no circumstance is KFC marking down $30 on their books because they issued coupons that somehow total to $30.
That said, I’m of the opinion that if a donation directly results in me receiving something in return… that’s not a donation. It’s a sale or transaction dressed in the clothes of charity. Plus, KFC sends coupons in the mail for free anyway.
From an urban planning perspective, there are some caveats to your points:
Cut-and-cover will make shallow underground tunnels cheaper to construct in almost all cases irrespective of building in an old city center or as part of building a new city center from scratch. In fact, older pre-WW2 cities are almost ideal for cut-and-cover because the tunnels can follow the street grid, yielding a tunnel which will be near to already-built destinations, while minimizing costly curves.
Probably the worst scenario for cut-and-cover is when the surface street has unnecessary curves and detours (eg American suburban arterials). So either the tunnel follows the curve and becomes weirdly farther from major destinations, or it’s built in segments using cut-and-cover where possible and digging for the rest.
At least in America, where agricultural land at the edges of metropolitan areas is still cheap, the last 70 years do not suggest huge roads, huge offices, and huge house lead to a utopia. Instead, we just get car-dependency and sprawl, as well as dead shopping malls. The benefits of this accrued to the prior generations, who wheeled-and-dealed in speculative suburban house flipping, and saddled cities with sprawling infrastructure that the existing tax base cannot afford.
It is, until it isn’t. Greenfield development “would be short term appealing but still expensive when it comes to building everything”. It’s a rare case in America where post-WW2 greenfield housing or commercial developments pay sufficient tax to maintain the municipal services those developments require.
Look at any one municipal utility and it becomes apparent that the costs scale by length or area, but the revenue scales by businesses/households. The math doesn’t suggest we need Singapore-levels of density, but constant sprawling expansion will put American cities on the brink of bankruptcy. As it stands, regressive property tax policies result in dense neighborhoods subsidizing sprawling neighborhood, but with nothing in return except more traffic and wastewater.
Either these cities must be permitted to somehow break away from their failed and costly suburban experiments, or the costs must be internalized upon greenfield development, which might not make it cheap anymore.