Treasure Map?? (BSM)

[Xiola]

Hi guys, I finally decided to buy the treasure map off the librarian. but it doesnt seem to show me anything on the map. I had already been to the secret base in the top left hand corner, does that mean I have lost my money?

I dont see any other new location, and I dont remember getting such a great haul from the Secret base when I found it through exploring either.

Could anyone tell me if I am doing anyhting wrong?