The points needed "float" based on each year's stats and, I think, by state. There will be a period during which only invitees can register. After that, there will be a more open period. They used to have "waves" of eligible people during that open period, but last year they just opened it up to anyone after a certain date.
If you go to DISCUssionn on the PDGA site and look back at archives of official announcements, you can locate what the process was for last year.