Ask HN: Should I launch my app without in-app purchases?

My app was recently approved today, but I read that paid apps get most of their traffic in the early days.

I want feedback on my app, and I'd like to make a little money back from it, but it's my first app and I need to test the idea.

Would adding in-app purchases later be a waste of time because traffic will be low? Should I just release now at a low price? It's a personal productivity app. I plan on getting most of my traffic from blogging as the app represents something I've cared a lot about for a long time.

I plan to Show HN soon, and I think I'd get more feedback if it was free vs. $1 or $3.