Players, although is not recommended to sell, as they are extremely rare.
Those amounts of gold above 100 in one pile were lootable in the first weeks of dragon lords' existence. Those dragons were first creatures which dropped more than 100 gold. CipSoft changed the 100+ gold stacks in 2-3 stacks with under 100 gold. A picture can be seen at http://www.tibiapic.com/show.php?v=Ad1y5RTjTeTT The overcharged goldstack was also once obtainable daily from Edron Dragon Lair. It was surrounding by 3 Dragon lords. A picture can be seen at http://www.tibiapic.com/show.php?v=fcr4hDThTTTT