After searching further, I found that there are many currency use same symbol.
(for example: USD$, TWD$, CNY￥, JPY￥)
of course, if you have any idea of this, you can suggest it here. thanks.
I think $ is not a good idea. It can bring too much bad attention. Also at this time it is not that important.
More important is to add SHA to coinmarketcap. I did make a request but they didn't add it.
Much more people would see SHA if it is on coinmarketcap.