It's the difference in installed cost between the two solutions that would need to be made up if you're doing an NPV calc on the energy savings to determine an ROI- a recirculation system worth owning isn't exactly free.
Even though a DIY POU tank install might marginally more expensive than a DIY recirculation system, the hardware costs aren't radically different and the tank could even be cheaper if he is going to run 120' of dedicated return plumbing, and there's no user-education required- the hot water is always there, the cold water is always cold, etc. (Not having to explain how your "fix" is better than what came before has to be worth something, eh? ;-) )
And yes, nobody cares about the energy use of the pump compared to the energy used to heat the water, even for the piggiest of pumps. The cost of that hot water will vary pretty dramatically depending on the fuel used and water heating method: An embedded coil in an oil or propane fired boiler gets to be pretty expensive in MI, but natural gas (either standalone tank or boiler) is pretty cheap. Electric rates vary widely, wouldn't even take a stab a how that compares without knowing which utility is supplying it.
Ballvalve: Yeah it seems odd how tiny tanks of any quality cost as much or more than standard sized tanks, but that's all about tooling, storage, & production volume. The little Bosch Aristons seem to hang in for quite awhile in some installations, but fail fast in others- not sure if it's a water-quality or what, but I've stopped recommending them. And they're not super-cheap either.