It would certainly be an expensive play. When he mentioned a 20 core system, I'm assuming it is some VM system, since I don't know of any 20 core CPUs. I'm guessing he is using DigitalOcean and he has two of them, so he is looking at $1000 a month in hosting cost.
It's an expensive side project for sure, but it doesn't have to be anywhere near as expensive as that.
My own side project uses a server with 20 cores (2x E5-2690v2 CPUs), with 256GB RAM and a 2TB SSD. This is a dedicated server I rented from tier.net in Texas, after seeing it listed on webhostingtalk [1]. It costs about $160/mo, and that's recently fallen further by paying for 3 months up front.