It has to be at least 30 minutes, otherwise you're really not providing much other than a speed run. I can show you a BT2 run in 1:45 but it doesn't mean I can do BT2 34 times per hour.
First off the crystals don't matter, I just sold all mine for 80k each and I didn't need to do squat. If they're really that cheap on Ruairi right not then great, but that's not 800k~1.5m without crystals. Explicitly the 1.5m.
you said nigh impossible though, he did it in the first run
and if 30-40s is fast, then 50s-1min is average
it doesn't matter because even if ur making 20k per minute that's still 1.2m/hr, then subtract repair costs, it mite b like 1-1.1m
obv the 1.5 is the high end of the estimate and it excludes repairs and shet, but you get the point, you're spawning gold at that rate
at the very least, with a group of 5-6k+ maxed out on reforges, ur gonna b makin 800k
comparing my claim to 500m an hour is completely uncalled for ^_^