how many confirmations is safe? (i'm buying 40btc)
i'm gonna meet him in a bank to be safe. and not gonna hand him any cash until i get the btc.
anything i should be concerned with?
Everything.
Confirm the source of bitcoins before you go there. Although there would be no way to trace the BTC to you, I still wouldn't get involved in something where the seller is obviously dodgy.
Any person holding 40BTC knows how much he can sell at. While getting quick cash can = discounted price, but the discount can't be unrealistic. If its a very big discount, do 2BTC trades, amount you are willing to give up. Just FYI, the risk doesn't end just because you are meeting at the bank:
1- Meet at bank
2- Transaction goes smoothly, he transfers first.
3- Follows you back to home.
4- Takes BTC kidnaps you because a guy willing to spend that money on bitcoin obviously has some more dough.
Would hope that doesn't happen, but I wouldn't go for such a transaction unless I have traded smaller amounts before and I am not in my own city. Meet at airport, do transaction. Get on a flight back home. Could still be followed but I am willing to take a smaller risk.
40btc is only 25k? what house doesn't have 25k worth of stuff. kidnapping me or following me home seems excessive, when any house has that amount and more.
(i don't live in a 3rd world country)
Mate its not 25k.
25k is liquid cash you are willing to trade. So many assumptions can be made about the persons net worth from that.
If it were at a decent discount I wouldnt blink too much. But as you mentioned its an big discount.
it's not 25k liquid cash. it's btc that i'll have. he will already have the cash, since a trade would have been completed at the bank. i think this makes a huge difference in their approach.