That's normal.
Rank 5: AP 40 + dragon bone (large) × 3
Rank 6: AP 40 + Rune × 3
Rank 7: AP45 + dragon bell (large) x 4
No idea what that last item is (I can't be arsed to dig up if Google-senpai fucked something up horribly like usual), but yes, R3 and R5 uses the same mats and R4 and R6 uses the same mats.