part1
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if u can live with made in china quality, get the OTA-R31 (~RM199) kit, then buy the CS upgrade kit (~RM50).
part 2
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then buy brushless motor + ESC (ezwing 9T ~RM250)
then a LiPo 5000MaH (RM80)
bluebird 631MGS servo RM80
remote (Tx / Rx) of your choice (RM130 - RM999)
you can upgrade part 1 later, but you can keep the part 2 and transfer to new chasis. so part 2 better buy at least mid range stuff. later kene racun u will upgrade also no matter what. lol.
try avoid RTR kit, u dont want the stock electronics

i'm still new, so u still need 2nd and 3rd opinion la