If you want to experiment with letting people try the app for free, you might want to consider just using a single permanent IAP purchase of some higher-than-$1.99 value (say, $4.99 or $9.99) that unlocks unlimited articles. Without this purchase, you could limit them to something like 20 or 50 articles. Enough for them to get a feel for what the app is doing and decide that it's worthwhile. The idea being that anyone that does send enough articles to hit the limit would likely have decided it's useful enough to be willing to pay the higher cost (which they may not have been willing to pay upfront if you simply charged that much).

Or you could just go back to your original price, since that was working out. It's hard to say which would do better.