RT-AX88U Pro vs GT-AX6000, why GT is much cheaper?

[RMerlin]

One MTK one is a TUF model that looks very different to the ROG model with Broadcom hardware.

Which is why full model names matter. There is no such thing as "an AX6000". There's a GT-AX6000, which is Broadcom BCM4912. And there is a TUF-AX6000 which is Mediatek MT798x. And there's also a GT-AX6000N which is Qualcomm IPQ807x - I believe that model never got launched. There's also the RT-AX89X, which is Qualcomm, and is also an AX6000 class router.