Yes, without spoiling it for anyone else, the value increases exponentially :)
(1 'silver' is worth more than 4 'copper')
Viewing post in The Square Root Of All Evil (LOWREZ Jam) comments
the exact values are (use https://rot13.com/ for the answer, it only goes up to gold):
n pbccre vf gjb uhaqerq svsgl fvk qbyynef
n fvyire vf guerr gubhfnaq friragl gjb qbyynef
n tbyq vf sbegl rvtug gubhfnaq bar uhaqerq naq gjragl rvtug qbyynef