Cheapest node to add to XT12 to create a mesh?

[mstar]

i know people will say get the XT8/9 but is there any other other options i can use which give me best speeds? would a xd4,5,6 etc be too much step down with the XT12 as my router?

I was thinking:

- ASUS RP-AX56 AX1800 Dual Band WiFi 6 Range Extender​

What do you guys think? or to really benefit from the option i really need a XT8/9?

I cannot afford another XT12 :-(