My 2009 Red Book shows the following for these Proof sets, are you sure they are Proof sets, vs Uncirculated sets?
Proof Set Iss Price/Curr Value Unc.Mint Set
1972 S Proof $5/$7
1972P/D/S Uncirculated $3.50/$9
1987 S Proof $11/$8
1987 P/D Uncirculated $7/$9
1976 S Proof $7/$12
1976 P/D $6/$10
The 87 S proof set also came out in a Prestige Set which included the Constitution dollar (Silver).
The 76 S also came out in a 3 piece silver set.
Hope this helps.


















