Excellent points by Des Traynor:
- Charge earlier than you're comfortable
- Charge more than you're comfortable
- Justify (or kill) your lowest plan
- Plan on changing prices
Each of those deserves highlighting, but Des already does a good job of discussing them in the article, so I'll just comment on the last one.
Pricing is a very tricky thing to get right the first time. Yet, in a world where we are willing to A/B test so many things, we are strangely reticent towards changing our pricing around dramatically. Yet the stories of startups that changed their pricing schemes (not just their prices, but also the structure of the way they charge) and multiplied their earnings abound.
Learning how much your product should cost to maximise profits should be very high on your list of hypotheses. Therefore, start testing prices early, rather than late. This will also help ensure that you fit your product to the right market.