Silver coins can be acquired mainly as reward from some quests, but you can find them also as loot from some creatures. Best known is Armageddon Roach. Also they can be found as loot in bosses in Mondain's Legacy dungeons.

Items available from Vendor stone in British Castle
Item	Name	Price
	Bone Throne	300
	Bone Table	300
	Haunted Mirror (east. south)	1000
	Mongbat Dark Board	1000
	Hooded Shroud of Shadows	2000
	Ethereal Chimera	2000
	Ethereal Undead Horse	2000
	Ethereal CuSidhe	3000
	Ethereal Charger Of The Fallen	3000
	Ethereal Hiryu	3000
	Ethereal Polar Bear	3000
	Cannon (east, worth, west, south)	1000
	Guillotine	1000
	Casket & Skeleton (east, south)	1000
	Chest of Drawer	250
	Chest of Drawer (red)	300
	Wall Sconce	150
	Wall Torch	150
	Globe of Sosaria	2000
	Horse Barding (east, south)	500
	Bone Couch (east, south)	500