Wah profit margin is a lot ya, if we get from taobao including shipping is 120 so 80 bucks for local storage and covering local warranty
If it is global version with local warranty, they have some justifications. Then it is whether you value local warranty and the global FW or not.
For example, if it adds VLAN function for SingTel ONT users, then it may well worth the money for SingTel ONT users.
FYI:
Asus RT-AX86U, China version, RMB1499 or S$300.
Singapore version: now exclusive to Singtel, S$17 * 24 month or S$408. It may be higher later to the general public. So you can say S$108 for local warranty and global firmware (said to be more or less the same).
Again, it depends on whether you want to take risks or not. IMHO Asus router HW may not be that famous in terms of HW quality. So 3 years of local warranty may be important.
TP-Link AX50 Korea version from Shopee: S$159
TP-Link AX50 Singapore version: S$209 when on offer.
So it will depend on people to see whether S$50 for 3 year Iocal warranty is worth or not.