Ok, here are some avg. prices for you based on current and completed ebay auctions
#2 - $4-5
#6 - $5, what color is the hair? There are two variants.
#7 - $3-4
#8 - $3-4
#14 - $4
#18 - $4
#26 - $4-6
#29 - $4
#53 - $3-4
#67 - $20-25
#74 - $3-6
#89 &90 seem to do better as a pair, anywhere from $8-20
#93 - $4-5
#113 - $10
#135 - $5
#136 - $5, $15 for orange hair variant
#142 - $2.50
#156 - $20
#157 - $4-5
#175 - $5
#205 & 206 - $6 for pair
#209 - $4-5
#221 - $5-10
#251 - $4-5
#255 - $5-8
#257 - $6
#260 - $6
#277 - $7
#278 - no single listings, I'd say $4?
#279 - $5
#280 - $15-30
#282 - not sure on this one.. $10?
#301 - $15-20
#307 - $12-20
#315 - $3-5
#358 - $4
#405 - $7
#429 - $3
#500 - $3-4
#566 - $8-10
#592 - $5-7
#802 - $5
Hope this helps!