Is there any evidence other that actually backs the notion that you save money on a serverless architecture? As far as I can tell, it feels like once you use this kind of mechanism, you're tied to AWS for the foreseeable future.
I did this analysis in my (admittedly crappy and rushed) pycon web talk - in some cases you can save a lot of money. In other cases you'll pay more. Skip to the 20 minute mark. Also I work for AWS so general disclaimer that I'm biased.
An interesting thing to note is that efficiencies in this space only increase. Which theoretically lowers prices. You also get some pretty rapid and massive parralellization when you need it. The pywren project has some insightful examples and benchmarks of teraflops of compute and 10s gigabits/s of data arriving as part of a single function call. It's a different paradigm that will transform a lot of workloads but not all.
It's hard not to get swept up in the frenzy around it.
