This 1899 Chicago Board of Trade contract shown sold on Sunday, December 11 on Ebay for $32.88. Compare this with the stamps used as examples in the price discussion for used documentary revenues in this post on December 13. While those used stamps have little value, those on this small futures memorandum of sale are a different matter. $32.88 is not a fortune, but it is +30x the value of the same stamps off cover and without distinguishing cancels.
The bidding for this item was interesting. It appears that three collectors or dealers placed "snipe" bids. All three snipers have an extensive Ebay sales or purchase history as indicated by the number of transactions.
Clearlly, by this bidding pattern, this is a document wanted by advanced collectors and dealers of material catering to those collectors. I can't be sure why this item was so popular with those sniping bidders, but I can take a guess:
Two special characteristics of this piece may have driven the final sale price above $30:
1. The cancels are special: big clear ornamental shields that neatly tie the stamps to the piece.
2. The memorandum has a statement regarding documentary tax requirements at the upper right. It reads:
For each one hundred dollars in value or fractional part thereof ONE CENT.
Immediately below this statement fall the stamps with a total of 15 cents in face value. This contract sold for $1500. The guidance regarding the stamp tax requirements is scarce; this document was used at the Chicago Board of Trade; I would guess that other CBOT traders might have used similar documents.