Your profile says Singapore so I assume that Best Buy isn't an option. Some of us have been shucking Best Buy 14TB drives on sale for Black Friday at $190, compared to the approximately $120 cost of that 6TB drive.
Unfortunately, I realize that this is sort of a US-centric strategy for mass storage. You are, however, better off finding disks that are 10TB or larger, because as of yet, those don't seem to come in SMR variants.
As @hendry mentioned, <8TB is SMR, 8TB is CMR. The SKU for CMR drives <8TB is EFRX, which have been rebranded WD Red Plus. so for 4TB its WD40EFRX. I accidentally bought a WD40EFAX drive ~6 months ago and haven't used it yet; fortunately I've been able to get a refund in light of the recent spotlight on SMR drives