Circulated $2 bills are worth $2 unless they have special numbers (radars, star notes, etc.).

Uncirculated 1976 are fairly common, as that's when they were introduced with the current artwork for the bicentennial. They are worth in the $3 to $4 range; a pair with consecutive numbers command a small premium (about $10 for a pair).

Uncirculated 1985 $2 bills are less common (because it's a less sexy year to collect), but the ones I've seen are still under $10.