Quote:Secondly,
ebay past sales (sold) are a decent indication of aftermarket prices, including the box with COA.

You also have to eliminate the high and low prices when looking at
ebay searches and make sure you check the boxes for both "completed" and "sold". This will give you a good idea of range. Patience will always get you a lower price.
For Gettysburg, I see a BIN that recently went for $190 (someone got a GREAT price) but based on the other sales I'd expect closer to $220-250. FWIW, Gettysburg went for $230 retail back in 2011. Good luck!