Imho it all depends on WHO you are trading to. If you're trading to someone from a big chinese company, whom daily gets their accounts locked down and stuff like that, you know where they buy mass accounts with level 1's just to sell gold from, so it's very easy for blizzard to track it down, and so they can see the IP the company is sitting at.
I remember when there was much gold selling in tbc and wotlk, and the seller told me that they daily had accounts shut down, so i should be very cautious (yes i was a noob back then, both at wow, and at buying gold xD). Which i also recieved a ban for, though i bought like 100 gold to gear my ?ber l33t lvl 19 twink, so was no biggie. But if that's the case, then do it safely, i.e the guild bank way or trade 10k at a time.
But if you sell / trade to someone who's just a regular guy buying gold, like people with regular non-flaggable accounts. I'd say go for trading 100k's. Since as mentioned before it could just be you were giving away the gold, since blizzard have no way of finding out that you are recieving real life currencies for the trade.
tl;dr
trade if you live like you dont care #yolo
