The 1923 $1 S.C. market price depends largely on condition and signature combinations. I'll say the Speelman/White combo at UNC, a good price would be around $95-$115.
If it's Woods/White then at UNC, should be $110-$140.
These are the common signature combos and mostly what you will see on auction.
Silver Cert.s is usually what new collectors acquire first when they enter into collecting U.S. currency. Most small-size types of Silver Cert.s are affordable and a nice way to get started.