About $5 retail.
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.
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 red seal indicates that your bill is a United States Note, a form of paper money issued until the early 1970s. Please see the question "What is the value of a 1928 B US 2 dollar bill?" for more information. All $2 bills and some $5 and $100 bills were issued as US Notes during the period 1928-1971, although the last "series" date is 1966.
There are 8 possible series letters on 1928 $2 bills. Please see the question "What is the value of a 1928 US 2 dollar bill" for details.To clarify things, the term "funny back" (or funnyback) wasn't used to describe $2 bills. It was applied to the rather garish design used on the reverse of 1928 and 1934 $1 bills. $2 bills carried the then-standard image of Monticello that remained in use until the $2 bill was redesigned in 1976.
Please check your bill again. There were no 1926 US bills; the date is most likely 1928.If so, there's more information the at question "What is the value of a 1928 G US 2 dollar bill?".
Please check again and post a new question. No $2 bills are dated 1929.If your bill's date is 1928, there's more information at the question "What is the value of a 1928 [letter] US 2 dollar bill?"
There were no $2 bills dated 1929. However, letters for the 1928 series go up to G so if that's what you have, please see the question "What is the value of a 1928 G US 2 dollar bill?"
About $5 retail.
Please check the bill's date - it should be 1928, and its type - it should be a United States Note.There's more information at the question "What is the value of a 1928 C US 2 dollar bill?".
the serial number does not match the series
All 1928 $2 bills were printed with red seals, so it's possible your bill has changed color due to age or chemical exposure. Please see the question "What is the value of a 1928 D US 2 dollar bill?" for more information.
Please check your bill again and post a new, separate question. "G" is the highest series letter for 1928 US $2 bills.
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.
A 1928 $2 bill, series D is only worth about $38 today. This varies depending on who you are selling to and what condition it is in.
"D" : $5 - $12; UN-circulated $45+
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?"