Along the way, the demons he killed, the monsters he eliminated, the beast hides he cut, and the demon skulls he boiled, all exchanged for about 600 coins, ended up being spent on buying three horses, leaving almost nothing left.
No choice, Yanmen's horses are expensive, especially in these wartime conditions. They've risen to 200 coins each, equivalent to the bounty for ten Golden Core heads!
Moreover, if Tie Dan hadn't been holding the Demon Extermination Order like a warrant, the horse dealers probably wouldn't have been willing to sell to him.
