A guy on the PSA board that runs two $10 blue flip bulk subs a year, was told he won't likely get the $10 rate again. So, since $15 with grading is the special rate, its possible $12-13 or even $15 is new low bar for no-auto grade submissions.
Additionally, the cards listed in the set aren't always the complete list of eligible cards. For sets that grow, like player sets, you can request the card be added if it fits within the description of that set type. Assuming of course that it is also listed in the books HOFMichael mentioned.