Sure you can.in 2 years time this amp will be valued 000, so i can resale it if its junk and get something new.
even after few days i can sale it if someone wants to get it for 50% off.
Why i need to spend 30.000$ for speakers?
can i go with 9000$ for speakers?
As I said it is a rough role of thumb to spent the majority of your budget on speakers, as speakers are contributing by orders of magnitude the most to sound (and not the electronics). Currently you have turned this rough general recommendation upside down with a 6k amp vs 1.5k speakers.
Again. Please it is your money and if it makes you happy and fits your circumstances- go for it. There are worse things in life where to (over) spent.