DrkLord
Galvanizer
This is unfortunate. Which brands are not using sealed drum...as bosch, lg, samsung, whirlpool have all been mentioned above as using one.In a way yes. Drum costs cover around 80% of the total so by not allowing to replace the damaged part, you are left to pay more amount whose costs rivals the new machine. You would rather go with a new one than spending on a depreciating asset.
It depends on which component actually goes bad. A major supporting one will warrant change of entire drum, a peripheral piece may not.
Again, as a suggestion, go for a brand which is transparent and not using some shady practices. You want your WM to run for at least a decade with minimum maintainance cost.
You can look into jugaadu stuff but once such machine or an important component goes down, it's days are already numbered.