The following prices are from the 4th Ed. of Canadian Bank Notes 2002.
Catalogue states that back proofs with one or more vignettes are worth 33% of face proof prices
and back proofs with only the bank name, lathework and counters are worth 25% of face proof prices.
a. 1888 Face Proof coloured - $10 - Ontario Bank 18-06Pa $600
b. 1888 Back Proof coloured - $10 - Ontario Bank 25% of face proof
c. 1897 Face Proof - $20 - Dominion Bank no info. in catalogue
d. 1897 Back Proof - $20 - Dominion Bank no info. in catalogue
e. 1888 Face Proof - $10 - Dominion Bank 12-06P $600
f. 1888 Back Proof - $10 - Dominion Bank 33% of face proof
g. 1899 Face Proof - $50 - Merchant Bank of Halifax 22-08P $700
h. 1899 Back Proof - $50 - Merchant Bank of Halifax 33% of face proof
I. 1901 Face Proof - $50 - Dominion Bank no info. in catalogue
j. 1901 Back Proof - $50 - Dominion Bank no info. in catalogue
k. 1905 Face Proof - $5 - Dominion Bank no info. in catalogue
l. 1905 Back Proof - $5 - Dominion Bank no info. in catalogue
l. 1922 La Banque National - $100,$50,$20,$10,$5 all specimen "60".
$100 22-10S $300
$ 50 22-08S $250
$ 20 22-06S $250
$ 10 22-04S $200
$ 5 22-02S $200
Again, these prices are not current but should give you a start. As Friedsquid suggested, a newer edition of the Charlton standard catalogue of Canadian bank notes would certainly be a worthwhile investment and may be more detailed.