I saw one posted for sale (with an impage of the bill) for $975 at http://www.thecurrencyhouse.com/index.cfm?pgx=goldcertificates I would guess anyone would want 10-25% of the retail price as a profit for finding someone with enough money and interest in rare currency. Under no circumstances should you deal with dealers who offer a free estimate to buy. They have a conflict of interest. If you can get a free appraisal that is your best course of action. I know someone who has one of these bills too.
Auction values for a circulated one range from $35.-$100., depending on how worn it is. Uncirculated specimens go for $300-$500
45.00
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?"
Retail is 5 to 10 dollars depending on how worn it is
The value of a 1928 Silver Certificate dollar is worth at least the amount of the face value. There are 6 different 1928 Silver Certificates, the value depends on the grade of the certificate. The best way to determine the value is to have the note appraised by a professional.
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?"
Yes. The 1928 series was the last for circulating gold certificates, and $10 was the lowest denomination. There's more information at the question "What is the value of a 1928 US 10 dollar gold certificate?"
45.00
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?"
Retail is 5 to 10 dollars depending on how worn it is
The value of a 1928 Silver Certificate dollar is worth at least the amount of the face value. There are 6 different 1928 Silver Certificates, the value depends on the grade of the certificate. The best way to determine the value is to have the note appraised by a professional.
About $5 to $10
In worn condition, about $200. In better shape, $400-500.
I can't find a listing for a 1928-A certificate. If the "A" isn't located right next to the date then it is something other than a series letter. A standard 1928 gold certificate can retail for $250 to $750 so I would advise having your bill appraised to be certain of its value.
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?"
Please check your bill again and post a new, separate question. There were no series letters on 1928 $20 gold certificates.
Please check your bill again. All HAWAII-overprint $1 bills carry a 1935 series date. There's more at the question "What is the value of a 1935 US 1 dollar silver certificate with HAWAII on it?"
The US Treaury only printed $10 Gold Certificates bearing the Series Date of 1928 and 1928A.