The cost of the Reforging Stone was extremely expensive. A single legendary grade Reforging Stone cost 500,000, and tens of thousands of forging fees had to be paid on top of it to reforge a weapon.
Aside from Apostles with an abundance of Lingxes to spend, regular people wouldn't choose to reforge their weapons. Of course, inveterate gamblers aren't considered regular.
There was no need for Lin Xun to pay the forging fee, but the cost of a 500,000-value Reforging Stone was unavoidable.
[…]
[You have used the 'Legendary Grade Reforging Stone' for the 'Shadow Slayer Fist Sword' reforging process!]
[Estimated reforging time: 13 hours 13 minutes 25 seconds…]
[Do you want to proceed with the reforging?]
[Reforging weapon, please wait patiently…]
[…]
[…]
The reforging time was half of the total forging time, but the forging fee charged by the 'Book of Trade' was just as much as developing a whole new weapon.