First effort gives me 6-22, so a range of 16.
hand: charm, igg, bank, bank, fortune
fortune, bank, bank, igg (no copper), charm (no $) = 6
fortune, bank, bank, igg (copper), charm (no $), copper = 7
bank, bank, igg (no copper), charm (no $), fortune = 8
bank, bank, igg (copper), charm (no $), fortune, copper = 9
bank, bank, igg (copper), copper, charm (no $), fortune = 10
bank, bank, igg (copper), fortune, copper, charm (2$) = 11
bank, bank, igg (copper), copper, fortune, charm (2$) = 12
bank, igg (copper), bank, fortune, charm (no $), copper = 13
bank, igg (no copper), bank, fortune, charm (2$) = 14
bank, igg (copper), bank, fortune, charm (2$), copper = 15
bank, igg (copper), bank, copper, fortune, charm (2$) = 16
igg (copper), bank, bank, charm (2$), fortune, copper = 17
igg (copper), bank, bank, charm (2$), copper, fortune = 18
igg (copper), bank, charm (2$), bank, fortune, copper = 19
igg (copper), bank, charm (2$), bank, copper, fortune = 20
igg (copper), charm (2$), bank, bank, fortune, copper = 21
igg (copper), charm (2$), bank, bank, copper, fortune = 22
You can make $24 and $26 as well but I can't see any way to make $23 or $25.
edit: forgot that bank would count fortune
edit: improved to 7-26, a range of 19:
hand: fortune (f), bank (b), bank (b), igg (i), igg (i); copper will be denoted as c:
fbbii = 7
fbibi = 8
fbiib = 9
fibib = 10
fiibb = 11
fiibbc = 12
fiibcb = 13
fiicbb = 14
fiicbbc = 15
fiicbcb = 16
fiiccbb = 17
ificcbb = 18
iifccbb = 19
iicfcbb = 20
iiccfbb = 21
iibbccf = 22
iibcbfc = 23
iibcbcf = 24
iicbbfc = 25
iicbbcf = 26