Your gut feelings are correct. I think that they had originally planned to let you buy them at some random event but then due to play testing, changed their mind. I know there are several threads on this, because I am one of them and was referred to a previous one....but the bottom line is that you can only purchase Sighting markers during the DYO or get one for free (if it is the correct year) due to a Reinforcement Event.
Ha! Actually my gut feelings were the ones where I wasn't sure and that questioned the logic of #2 and wanted to make sure I wasn't missing something.