Scratch

You could make new sprites and there costumes the numbers 1,2,3,4,5,6 etc.  if you have costume 1 name it "1" scratch will then rename it "11"(ignore it) etc. ,control them with a variable "Forever
   if Show=1
           show
   else
     hide"

example of how to display it:

when gf clicked
forever
 set (Gold_1) to <(letter 1) of (Total_Gold)>
if <(show) = [1]>
  switch to costume (Gold_1)
  show
else 
  hide

now when you want to buy something from the "shop"

when gf clicked
forever
if <(show) = [1]>
if (touching color [red]?)                                   //can be a sprite as well 
  say [This health potion costs 20 gold pieces]
 else 
  say []
end
if  (mousedown?) <and> (touching color [red]?)
  change (Total_Gold v) by [-20]
  change (HP_potion v) by [1]
  say [ you bought a Health Potion for 20 Gold Pieces]

Just an example of what you mean by the Money part,hope it helps