They are worth $5 in mint uncirculated condition, dropping to $1 in Very Good used quality.
Value is dependant on denomination and condition. Most smaller denomination notes are worth $4-$5 in mint uncirculated condition.
The 1923 Reichsbank 20,000 Mark note in uncirculated condition is worth $2.
The value of a 1914 50 mark note can vary based on its condition, rarity, and demand from collectors. In general, these notes can be worth anywhere from $5 to $50 or more, depending on these factors. It is recommended to have the note evaluated by a reputable currency dealer or appraiser for a more accurate valuation.
The 1923 German Mark 200,000,000, Note is very rare; High Grade Score, 90 in today U.S. Dollars can cost $250 and in good condition can be unlimited in the Auction or Collector's Market Value ! If one of 200,000,000 German Mark Note can be found. . . Living Life Enterprises Presents.
About $2 US.
There are three versions of the 1910 issue German 20 Mark note. The more common have no watermark and are worth $80-$100 in uncirculated condition ($30-50 in Very Fine). The less common example with a watermark reading "20 Mark" is worth $350 in UNC and $150 in VF.
Yes, the German Bundesbank will exchange any Duetsche Mark note or coin free of charge to Euro. See related links.
There are two versions of the 1980 10 DM note. The more common has "(c) Deutsche Bank 1963" on the back and is worth $12 in perfect uncirculated condition. The less common version does not have the copyright notice and is worth $25 (in UNC condition). Both notes still have a collectors value in Very Fine condition ($7 and $10 respectively) but any normal worn note is worth it's face value - they can still be exchanged for their Euro equivalent - see related link.
Since adopting the Euro in 2001, Deutsche Mark notes are no longer legal tender. They have a replacement value (in a German bank) of approx $7.50. A 1989-1999 uncirculated 10DM note is worth between $10-$20, depending on signature.
A perfect uncirculated note with a 7-digit serial number is worth $10. Ones with only 6-digits are worth $30. ($0.50 and $2 in Very Good, crisp used condition).
Priceless. The first Federal Reserve Notes were printed in 1914.
The "4-D" indicates you have an early Federal Reserve Note; those are the code number and letter for the Cleveland OH district. There's more information at the question "What is the value of a 1914 US 5 dollar Federal Reserve Note?".
Please check your bill again and post a new, separate question. No $1000 FRNs were dated 1914.