> I know not every researcher or entrepreneur has the resources of NVIDIA to train for this many days, but let's not forget, that part needs to occur only once.
It's not like they trained this on a GPU farm. According to the paper [1], they "trained the network on a single NVIDIA Tesla P100 GPU for 20 days".
[1] http://research.nvidia.com/sites/default/files/pubs/2017-10_...