I mainly make ABS filament in 2.8mm. I tried poly carbonate but was not fully successfull and needs more tuning to get right.
The cost of the ABS granules is about $5/kg . Polycarb is a bit more expensive around $8/kg.
It would be nice to recycle wrong prints, but never done it. There are several problems with recycling: You need someway to grind it down. Then there is the issue that any pollution picked up will jam the 3d printer extruder. And you need to mix it 50% with new material due to the deterioration of the plastic.
Masterspool has the risk that the filament get tangled. Also switching between colors is a hassle. SO much easier to have spools ready to be used, and if they empty, fill them again.