Running a script for a few hours a day (10-14h), playing some hours aswell, and account is offline for like 6-7h per day, no ban here either, using AutoIt only, ofc.
I will however, stop for a while, to see if AutoIt is completely safe or not.
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Last time I checked, Blizzard is against gold buying/selling through third party systems, so, if you wish to be safe, do not engage in gold for money transactions that aren't proccessed through Blizzard (read: RMAH, when it comes out), because they do keep an eye on that, and they will get you banned for that, the more you sell/buy, the more likely you are to get banned.
To OP: you sold 350million gold, assuming you're not a retard and you're selling them for at least 10$, you will have at least 3500$, enough to buy a shitload of game copies and whatever you want. Just put a few more hours into it, bot a char or multiple to 60 again, and sell 700m until you get banned again. Rinse and repeat, quit your job, live a happy life.