In my country hydroxylamine sulfate 1kg ( 10 euros) For 1 kg pure silver. And 5 litre 25 % ammonium hydroxide pride 6 euro.
16 euro price for 1 kg 999 silver recovery.
I'm referring to the equipment and how you would be able to deal with a larger volume, more than the costs. Obviously you wouldn't want to be doing a few grammes at a time.