There were no series letters on 1923 $1 United States Notes; you may be looking at a plate position indicator or some other "housekeeping" mark.
In any case this is a moderately valuable bill compared to its blue-seal silver certificate cousin. As of 06/2014 approximate prices are:
Circulated: $90 to $150 depending on the bill's condition
Uncirculated: $400
Serial Numbers
A bill's serial number is a counter and a security feature. In most cases it doesn't affect a bill's value or help to identify it. Some collectors specialize in bills with low serial numbers (e.g. 00000005) or unusual patterns (12344321) so these can bring above-average prices.
DISCLAIMER: The values quoted are market averages as of the date shown, but may be different for an individual bill due to variations in quality and other factors. Also the wholesale (buying) price of a bill will be less than the selling (retail) price. A reputable currency dealer will be able to give a more accurate valuation based on an in-person inspection.
The blue seal indicates your bill is a silver certificate, a form of paper money issued until the early 1960s. There's more information at the question "What is the value of a 1923 US 1 dollar silver certificate?".
The U.S. didn't print any $2 bills dated 1923. Please check your bill and post a new question.
There were no $2 bills printed with the date 1923. If you mean 1928, please see the Related Question for more information.
If it is a blue seal silver certificate it is worth about $325 in very worn condition. That value could go up to $800 with less wear.
Normally it would be necessary to request a specific date, but the only bills that fit your description are dated 1923. Please see the question "What is the value of a 1923 US 1 dollar silver certificate?" for more information.
The blue seal indicates your bill is a silver certificate, a form of paper money issued until the early 1960s. There's more information at the question "What is the value of a 1923 US 1 dollar silver certificate?".
Please check your bill again. 1923 and 1928 are the only dates in the 1920s for red-seal $1 bills.
What is the value of a 1923 ONE DOLLAR DOMINION OF CANADA BILL. The serial numbers are printed in red. The letter D appears on the right and left side of face of the bill. The number 2 appears to the right of seal of the Department of Finance
The U.S. didn't print any $2 bills dated 1923. Please check your bill and post a new question.
what is the value of a 1953 two dollar bill with a red seal
There were no $2 bills printed with the date 1923. If you mean 1928, please see the Related Question for more information.
If it is a blue seal silver certificate it is worth about $325 in very worn condition. That value could go up to $800 with less wear.
$10
Normally it would be necessary to request a specific date, but the only bills that fit your description are dated 1923. Please see the question "What is the value of a 1923 US 1 dollar silver certificate?" for more information.
The exact value of a 1928 red seal two dollar bill would actually depend on a number of factors. Most importantly, the condition of the bill.
Please check your bill again and post a new, separate question. The last red-seal $10 bills were large-size United States Notes issued in 1923.
The value of a 1963 red seal two dollar bill is $1.00 to $1.25 more than face value if circulated. It is worth about $10.00 if uncirculated.