Back when that top note was first issued in 1910, 1000 marks was quite a lot of cash - about US$300 at the time. However, as the war progressed and eventually was lost, the mark began it's decline, eventually reaching the hyperinflation of the early 1920's. Notes with this design and date were issued right up to 1922. Seven-digit serial numbers indicate a post-1916 issue; these aren't as scarce as six0-digit examples.
The bottom note doesn't show Hitler himself, it's just a generic, stereotypical Aryan youth. As an aside, you might want to check the watermark on this one; it should be a "5". If it's upside-down with respect to the rest of the design on the note, it's the scarcer "error" variety.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis