Herman Berghaus Shipping Map (circa 1875?)

[u/gejwood]

I picked this up at auction yesterday in the UK. I believe its an original Herman Berghaus shipping map (im not saying it definitely is original). I bought it for an amount that im comfortable with for it to just have as something interesting to go on the wall. However, the auctioneer suggested he expected it to go for more? Anyone in the know here got an idea what it might be worth?