He gives you the map to the Old Mine on Diego's say-so (you can pay, argue it should be free, or take it by force); this map is what lets you reach the Old Mine.
Old Camp — Chapter 1: Sells maps; he provides the map to the Old Mine.
Items Graham sells in Gothic 1 Remake.
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Graham can be found in the Old Camp (Shadow).
You: I want to buy a map.
You: Hey. I'm new here.
Graham: Oh, how proper of you to introduce yourself. I'm Graham, the mapmaker. What're you after?
You: Diego sends me. He says you could give me a map that shows the way to the Old Mine?
Graham: Ah, a friend of Diego's. Sure. That'll be twenty nuggs.
You: I'm not paying. Give me that map or I'll just take it from you.
Graham: Whoa! Calm down, will you? Here - take the bloody thing and leave me be.
You: I'll see you later.
You: Wait a minute. Diego said you'd GIVE me a map. Not sell me one.
Graham: Diego can say what he likes. D'you even know how long it takes to make one like this?
Graham: Twenty's already a special price. Normally, you'd be lookin' at fifty.
You: Here are the nuggets.
Graham: Cheers. Trust me, that was a right good price.
Graham: Where? Go get your nuggets first, then we'll talk. Maybe bag some game or pick a few mushrooms - folk round here will give you a fair price.