The DMG has some hireling costs, too, on a table in the Campaigns chapter. None of them in the DMG is called 'sailor' or whatnot, but there's stuff listed there like laborers, craftsmen, mercenaries, mercenary leaders, lackeys/valets, porters, teamsters, and such. Arms & Equipment Guide has more, but the DMG does at least have around a dozen or more typical hireling costs listed.
Obviously, seafaring books would probably have some such costs related to ships and sailors. Dunno if Stormwrack does or not. Seafarer's Handbook by Fantasy Flight Games has costs for various kinds of sailing ship crewmen, IIRC, and that's the only seafaring book I have for D20 or D&D at present.