Hey, thanks for the kind words. I wasn't able to mention the costs in the post (might follow up in the future) but it was in the hundreds of dollars, so was reasonably accessible as a hobby project. The GPUs were surprisingly cheap, and was only scaled up mostly because I was impatient :) --- the entire cluster only ran for a few hours.
Do you have any links to your work? They sound interesting and I'd like to read more about them.