Hi I'm new to cryptocurrency investment. But recently I just realize that most of the crypto exchange platform didn't support Malaysia like Luno (Stop purchase bitcoin from credit card service), Coinbase... So the only option left is Remitano and Localbitcoin. Would like to ask is there any other cheapest way to buy bitcoin in Malaysia? 
I think buying at Localbitcoins is not safe as it involves peer to peer interactions. There are many scam reports about that on various platforms. You can buy cryptos with credit or debit card on exchanges that is supported in Malaysia. There are many exchanges that supports buying with credit/debit card in Malaysia - CEX.io, Changelly, Coinmama, Coinswitch etc. If you want to buy at the cheapest price then compare the fees charged at different exchanges and buy at the best rate.