Full fingered gloves and/or mitts depending on how cold you want to go ... <$5 from your local $$ Store or Walmart.
Booties ... $30-$50 from MEC
Base layers ... merino wool from local thrift shop $5-$10; from MEC $50ish; and/or polypro from Sierra Trading Post $10-$20
Balaclava for really cold days ... <$20 MEC
Headband for coolish days ... <$5 $$ Store
Neck gaiter to prevent cold air from rushing down your neck ... <$5 $$ Store
Tights ... <$20 Nashbar or <$15 Walmart (Ladies sports wear section)
Extra top layers ... wool from local thrift shop $5-$10