You have to look at the top exchanges order books. You will see what price points sellers are putting there coins. There might be 10,000 coins for sale at $270 so that would be a wall that would take some time to break through.
Orders can be moved instantly. Don't put all your trust in the orderbook.
I would say to use charts. You can see areas where the price spent a lot of time, signifying a decent amount of support/resistance. Highs, Lows and trends.