United Kingdoms

Someone explain to Mentu that credit and quests are different options.

And you're going there too... What do credit and quests have to do with each other? I'm not even saying they're related.
But in real life, a lender makes sure you're able to pay. There's a system of collateral, and your salary must be enough to pay off the loan.
Since Lex doesn't have any other job besides the one the guild offers, and the guild simultaneously offers a loan without hesitation, then... Draw your own conclusions.