How long does it take to get your code from green man gaming

Should be instantaneous. At least it was when I bought DoW2

Instant for me. Unless they are advertising a shortage of keys, there should be no problems.

Unless you're preordering something or they're short on keys (like people have said) you get it within minutes. And if your mail with the key gets lost or something they've a library on their page where you find all the keys.

5 dollars is about 3.94 euros, try to buy from someone in steamtrades

Instant! They actually have scripts that see where your mouse cursor is and if its above the pay button, they just send you the code so you get it even before you click "pay now".