wait till I make a new post? seems like I have to wait 2 minutes..

It's 2 minutes for new users, with a higher post count it will go down to 30 seconds.

When above 50 posts it will decrease to 30 seconds.

Make sure that when you are posting in the "Diablo II" client trading grounds that you follow the four hour bump rule and that you do not post more than one topic in the top fifty topics presented.