Generally the only wasted resin is what you use if you make supports. You need to make holes so unused resin can drain back into the vat (if the item doesn't already have a path for draining). You can reuse the vat of resin until there's not enough left for whatever you want to print (basically indefinitely). My understanding is that over time you get dust/particles and other impurities in the vat and might have to dispose of the resin if you get too much pollution in there.How much resin is wasted per print? Can you reuse the resin? How many times before you need to completely trash whatever is left and start from a new batch?
I haven't got the printer yet, so I'm just regurgitating what I've seen in youtube videos and product manuals.
I'm under the impression that the 1kg/1liter container of resin will last for a long time. Much in the same way that a 1kg spool of filament will last a while.