The only US bills dated 1957 are $1 silver certificates and these had blue seals.
The nearest dates for red-seal $2 bills are 1953 and 1963. There's more information at the Related Questions.
At least one dollar
The fact that it has a T in the serial number neither identifies the bill nor affects its value. 1957 is the most common date for $1 silver certificates. In anything but top-quality condition it's worth at most $2, generally closer to $1.50.
1957 is the most common series for $1 silver certificates. Starting with a K adds no extra value. They're worth $2 to $3 on average.
About $9 - $10 if it is in uncirculated condition.
1957 $1 silver certificates aren't rare. In general they're only worth about $1.50 in average condition. The "P" at the start of the serial number doesn't help to ID the bill. Serial numbers are counters and a security feature but rarely affect a bill's value. Some collectors will pay extra for numbers with a special pattern, e.g. 12345678, or low numbers such as 00000015.
At least one dollar
1957 silver certificates are common among collectors and retail for about $1.25 - $1.50. A bill's serial number almost never has anything to do with its value and doesn't help to ID it.
The fact that it has a T in the serial number neither identifies the bill nor affects its value. 1957 is the most common date for $1 silver certificates. In anything but top-quality condition it's worth at most $2, generally closer to $1.50.
About $1.25. These are quite common among collectors. As you've seen from other posts, a bill's serial number is unimportant to determining its value.
Sorry but five bucks not too rare
About $1.25 As you've seen from other questions, a bill's serial number is not needed to determine its value.
30 to 50 pounds
1957 is the most common series for $1 silver certificates. Starting with a K adds no extra value. They're worth $2 to $3 on average.
Your note is worth about $1.25 if circulated, maybe $3 if uncirculated.The serial number is not a determinant of value unless it's "special" in some way, e.g. a low number like 00000002 or a pattern such as 12344321 or 12345678.
About $9 - $10 if it is in uncirculated condition.
1956-1957
1957 $1 silver certificates aren't rare. In general they're only worth about $1.50 in average condition. The "P" at the start of the serial number doesn't help to ID the bill. Serial numbers are counters and a security feature but rarely affect a bill's value. Some collectors will pay extra for numbers with a special pattern, e.g. 12345678, or low numbers such as 00000015.