Series 1957B silver certificates are actually quite common--they printed over 700 million of them. The value is going to depend on the condition, and also if there is a star at the beginning of the serial number.
If you've got a normal bill (that is, one with a letter at the beginning of the serial number, you could sell it to a dealer for about $1.50 if it's worn about like the average bill you'd get in change. If it shows no sign of circulation at all, that might go up to $6.
If your bill has a star at the beginning of the serial number, that means it was a replacement for a note that got damaged during production. Figure about $2 if it's worn about like an average bill, and $8 if it's uncirculated.
Those figures are just "ballpark" estimates. A dealer might legitimately offer you more or less, depending on circumstances.
BTW, because of the way bills are dated, the year on the bill is almost never the year it was actually printed. In the case of the Series 1957B $1 Silver Certificate, they were all printed in 1963.
Source:
Third edition of "A Guide Book of United States Paper Money" by Arthur and Ira Friedberg for values