I was also looking into this recently and DDR almost got a domain as well. Would love to have a .dd domain these days in Germany. I also considered an .su domain but didn’t get as far as you did just based on the price alone.

In terms of lemmygrad an AES domain (cn, vn cu for example), or if that’s also too risky one of the newer TLDs that are more or less free to take for whatever a person wants.