[DanielSong39]

Marlhait explained in episode 6 that the royal family imposed a number of duties and taxes in order to cut their losses short - which reduced the profits for the Milone company. All Lawrence was left with was 120 Trenni plus 1000 for his services (which was used to pay Horo's bills and obtain a cart load of pepper).

The exchange rate between Trenni silver and Lumione seems to be between 35 and 40-1 (otherwise Lawrence would've never accepted the merchant's initial deal). Horo's trick drove up the price 1.5 times the original asking price AND Lawrence insisted on a double margin on armor.

Unfortunately the market for armor collapsed completely, well below book value. Lawrence cannot get out of debt by selling it at a firesale price.