@Psychronia
The guild probably also deals in high risk stuff... For a price. In general, the riskier a quest, the more money you have to put up for adventurers to consider it. It's normal. But if you go without the guild, you have fewer expenses (because the guild takes its cut), so the price is lower for the risk of the quest. However, you also forego the guild's services, which include matching the quest with the adventurers, and probably making sure there's no funny business of either side (adventurer or client).