Despite its age, most of these bills retail in the $6 to $10 range in average condition. The only exception is a bill with a small F next to the date; these go for $8 to $13.
Prices for nice uncirculated notes are much higher though. As of 01/2011:
No letter: $65
"A" : $100
"B", "C" : $40
"D" : $210
"E", "F" : $35
Red printing
Nearly all United States Notes were printed with red seals and serial numbers. US Notes are now obsolete but were issued from 1862 to 1966.
The green seal indicates that it's a Federal Reserve Note. Please see the question "What is the value of a 1928 US 5 dollar Federal Reserve Note?" for more information.
Your bill is called a United States Note rather than a promissory note. There were eight different subseries within the 1928 series date; please see the question "What is the value of a 1928 US 2 dollar bill?" for specific information about values.
The green seal indicates that your bill is a Federal Reserve Note. Please see "What is the value of a 1928 D US 5 dollar Federal Reserve note?" for more information.
Could you check your bill again? A red seal would indicate that your bill is a United States Note; the first $2 FRNs were dated 1976 and have green seals. If you have a US Note, there's more information at the question "What is the value of a 1928 US 2 dollar bill?"
The green seal indicates that your bill is a Federal Reserve Note. All 1928 B $20 bills were printed as FRNs. Please see the question "What is the value of a 1928 B US 20 dollar bill?" for more information.
The green seal indicates that it's a Federal Reserve Note. Please see the question "What is the value of a 1928 US 5 dollar Federal Reserve Note?" for more information.
Your bill is called a United States Note rather than a promissory note. There were eight different subseries within the 1928 series date; please see the question "What is the value of a 1928 US 2 dollar bill?" for specific information about values.
The green seal indicates that your bill is a Federal Reserve Note. Please see "What is the value of a 1928 D US 5 dollar Federal Reserve note?" for more information.
A denomination is needed. Please look for questions in the form "What is the value of a 1928 A US [denomination] dollar Federal Reserve Note?" for specific information.
1928 $50 bills weren't issued as silver certificates. Please check the wording across your bill's top front; then see one of the following questions:"What is the value of a 1928 US 50 dollar Federal Reserve Note?""What is the value of a 1928 US 50 dollar gold certificate?"
Not every old bill is automatically a certificate so it's important to check carefully. If it has a gold seal and says "Gold Certificate", see the question "What is the value of a 1928 US 10 dollar gold certificate?" for values. If it has a green seal and says "Federal Reserve Note", it's not a certificate, it's a Federal Reserve Note. See the question "What is the value of a 1928 US 10 dollar Federal Reserve Note?" for values.
1928-series $100 bills weren't issued as silver certificates, only gold certificates and Federal Reserve Notes. Please look at the bill's front to determine which you have; then check one of the following: "What is the value of a 1928 US 100 dollar Federal Reserve Note?" "What is the value of a 1928 US 100 dollar gold certificate?"
Could you check your bill again? A red seal would indicate that your bill is a United States Note; the first $2 FRNs were dated 1976 and have green seals. If you have a US Note, there's more information at the question "What is the value of a 1928 US 2 dollar bill?"
1928 $50 bills were issued as gold certificates and as Federal Reserve Notes but they're not the same. Please check the wording across your bill's top front as well as its seal color*; then see one of the following questions: "What is the value of a 1928 US 50 dollar Federal Reserve Note?""What is the value of a 1928 US 50 dollar gold certificate?"* Gold certificates have gold seals and FRNs have green seals.
The green seal indicates that your bill is a Federal Reserve Note. All 1928 B $20 bills were printed as FRNs. Please see the question "What is the value of a 1928 B US 20 dollar bill?" for more information.
In worn condition, about $5. In better shape, around $10.
Please don't assume that every old bill has to be a silver certificate. 1928 $10 bills were issued as gold certificates with gold seals and as Federal Reserve Notes, with the familiar green seal and the words "Federal Reserve Note" across the top.Please check the bill's seal color and wording across your bill's top front; then see one of the following questions:"What is the value of a 1928 US 10 dollar Federal Reserve Note?""What is the value of a 1928 US 10 dollar gold certificate?"