If you want to buy Bitcoin for fiat (especially not USD/EUR/KRW but some less popular fiat), you might not have many options to choose from. You can try setting a deal with someone on this forum with the usage of an escrow service. I think it costs something, but probably not much. If you are okay with buying Bitcoin for USD, you can choose one of the exchanges that has this trading pair from this list: https://coinmarketcap.com/currencies/bitcoin/#markets. It's also helpful that on coinmarketcap you can click on the exchange and find the info about fees fast.
I prefer to use local exchanges listed on https://www.bestchange.com/, it works best for my local fiat (the fee is around 3%, sometimes a bit higher).