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
The value of a 1957 silver certificate dollar bill with a star in front of the serial number depends on its condition. In circulated condition, it may be worth slightly above face value to collectors. In uncirculated condition, it could be worth around $10-20 to collectors. The specific serial number does not significantly impact the value in this case.
Oh, dude, you're asking me to pinpoint the value of a specific dollar bill from 1957 based on its serial number? Like, I'm good, but I'm not a psychic, man. You might want to take that rare bill to a currency expert or something if you're looking for an exact value.
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.
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
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.
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.
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.