Those are a beautiful grouping of cards, all 1889 examples except the Fields (1887). Excluding the Harry Wright, there are no real stand-outs. I'd say the prices Kevin Struss (Baseball Rarities) used on his grouping of SGC graded cards are as good as any (fair market value).
http://www.net54baseball.com/showthread.php?t=127530
Note, his cards were similar photo quality as yours (from the Alan Sassoon collection).
SGC 40 => ~$200
SGC 50 => ~$275
SGC 60 => ~$350
SGC 70 => ~$425
SGC 80 => ~$500
Now they could be worth far more if more than one guy is looking for a particular player or pose.
Best of luck with the cards.