Fortune
???
Answers to clues:
ACROSS
(Item, pt. II)
(Item, pt. III)
MANN ACT (MANNA + CT)
NONZERO (N + ONZE + [st]RO[ve])
SLIM JIM (SL[y] + MIMI reversed, "getting" J)
(Item, pt. I)
DOWN
BIOTA (B + IOTA)
ELLEN ([h]ELLEN[e])
INT'L (LINT anagrammed)
JENI (JE + IN reversed)
MOONSET (NOT SOME, anagrammed)
SNOBDOM (MOB DONS, anagrammed)
TORIC (TORI + C)
Arranged in a 7x7 barred grid with mirror symmetry:
So "What you should bring us, part I/II/III" are thus "ten billion dollars." When they bring $10,000,000,000 they get the answer, SILVERBACK.