IMO encoding is just not that worth it these days. Storage is relatively cheap. An 8TB HD can hold 200+ bluray discs as is (assuming we are talking 30-40TB each). Lets say encoding lets us store 400-600 movies in the same amount of storage (going to argue that this is stretch at quality).

Is the $100-$200 savings worth the extra time spent (also computing/gpu electrical costs.

There's a reasonable argument that the cost in electricity would be measurable, perhaps small, but still measurable, if it's 1c per movie, not such a big deal, if its 50c a movie, one didn't actually save any money in practice. if one wants to software encode to get the best results, cost is going to be more than if one is ok with gpu encoding and just ok results from fixed encoders. (I would hazzard software encode at reasonable quality is going to be in the 25-50c cost if paying 25c a kwh)

If one lives in an area where electricity is cheap but storage is more expensive, the calculation is different.

Now, I'd note that there is one thing that storage being cheap can't directly solve. The ability to keep them online at a time (i.e. many computers are limited to the number of connected devices). In that world, one can argue that reducing that complexity also has value.