Unlike the castles around Crossroads Tavern, this castle has little agricultural production attached to it. The Lord Andelhelm founded this castle because he loves to fight orcs. The mountains surrounding the castle are filled with orc tribes.
Andelhelm has a band of anywhere from 20-120 knights at his castle together with about half as many ladies, with a garrison of 30 crossbowmen and 30 or so servants. It's battle with orcs, jousts and banquets at the castle virtually all the time.
Lord Andelhelm can afford this because he slew a dragon and seized its hoard. He also discovered 3 silver mines near the castle's location. Each of these mines is now being worked by miners (some dwarf, some gnome, some human) paying a tribute to the castle. There's a small farming village near the castle too, but most goods are imported.