18k to 21k is 'standard' pricing for internal 8TB drives (primarily for CCTV) here in India. External drives are sold at a lower price to clear out excess inventory for the manufacturer (this is why shucking doesn't always guarantee a particular model). And they need to clear out inventory to learn about failures rates and then run the next batch of manufacturing.
HGST have publicly stated they don't do failure testing because it's so expensive. 1 Million MBTF (mean time between failures) means that one drive out of one million drives fail in one hour of testing. And instead HGST will silently introduce new model/technology at the older rating and will wait on market feedback and adjusts their MBTF accordingly. Sales of external drives help speed this process up. This is why Seagate's 16TB external is sold at half the price of the internal drive, even though they are the same model. They need the failure statistics, sales of the internal drive aren't happening in enough volume. The price difference at lower capacities like 4TB doesn't even exist because those models already have their failure statistics.
But yes
@aslisuperman09 20k is an insane price jump from 12.5k a few days before. Is this the situation with other shops in your area? I'll try and see what local pricing is tomorrow here for you.
There's no achievable ROI for someone buying drives for Chia, not at the current network saturation and trading price. Anyone buying drives for Chia today is just throwing money away.
