I haven’t taken Arpit Bhayani’s course but really like the passion with which he explains every concept. Also his courses seems to give you a real taste rather than preparing you up for any interviews as they are just superficial.
I think you don’t need to pay for any course to get ramped up in lLD and HLD. Just see free youtube videos and will be up to mark.
For LLD, will definitely recommend Concept&&coding from Shreyansh Jain. Earlier it was free but little money invested and you will learn all there is to LLD.
HLD can read Grokking books, can look at channels from Gaurav Sen. I think he is the real originator for all this stuff atleast in India.