In Bale's Mage Tower.
...
After receiving threats from Darris, Link made sure to keep under the radar and did nothing that might arouse suspicions.
In recent days, he did not interact with anyone, nor did he even contact Herrera and Eliard. Instead he stayed cooped up in his room all day and all night, ostensibly to prepare magic scrolls.
He'd been consistently producing 15 first-rate magic scrolls a day, and all of them were handed to Derek to manage. He got three gold coins for each of them, thus earning 45 gold coins a day.
From the sales of magic scrolls alone, Link had so far earned nearly 300 gold coins. But wealth wasn't the only thing he gained recently.
