Hello I am ABDULRAHMAN
i just wanted to make sure before I buy Bitmain Antminer S9 13.5 TH/s
Can I run it to mine on Kaspa ?
Who wanted to sell you such an ASIC and for what price?
This is a very old asic, which gives little profit even on free electricity and its price is no more than $ 40 for 1 asic with a power supply. With a wholesale purchase of 5 pieces, the price can be in the range of 25-35 dollars.
Learn modern asics on this site
https://www.asicminervalue.com/and stay away from old hardware unless you're a pro.