Gold Buying isn't advised if your noob, it will definitely harm your In-Game rep.
I usually do this
Buy 10K NX
Sell for 1 Mill (that's how much it usually goes for)
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Process:
1.) set up a meeting point
2.) Buyer: 2 Checks of 500k, Seller, NX code ready
3.) Give the buyer 10 Characters, of the Nexon code for 500k,
With 1/2 of the code the buyer can see if its real or not, (can't cash it in without the full 20 Characters)
4.) after confirmation, give the buyer the rest of the code for 500k.
5.) Bam you have just made 1 Mill.
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I'm, against gold buying, it's too risky, and the chance of a IP ban.
And I don't like the idea very much.