You'd have a hard time getting $200 for that in a house auction or even on ebay...I find it hard to believe that two people reading Net54 have offered $600 for that. Sorry if that sounds harsh, but I think you're trying to drum up unreasonable offers by making that claim.
Check this auction by REA where two actual Brooklyn baseball team programs from 1889 and 1890 sold for a little over $1,000 for the pair.
http://www.robertedwardauctions.com/.../2006/671.html