bucket91
Your budget is a bit light for the best 12AU7s, as they are disappearing fast right now; and new stock just does not seem to be coming on line. $100 each will get you better tubes; but as others have suggested, give Brent Jessee a call....he's got his finger on the pulse.
From my personal experience and preference in the $100 and lower: $100 Amperex E80CC/6085 (12AU7 compatible) early 1960s gold pins, $90 Mullard 12AU7 1960s "Shield logo", $99 RCA 5814 or 6189 (12AU7 compatible), $49 RCA 12AU7 Blackplates 1950s, $49 RCA "Clear Tops" great tubes that are disappearing fast (you will love them or hate them....I love them)