Adding one thing to the compare-with-similar-games approach that I have not seen in this thread yet: comparing prices is a snapshot, but prices on Steam and itch are really a time series. The sticker price matters less than the discount rhythm, meaning how deep and how often your closest comparables actually discount. Two games both listed at $10 are not in the same market position if one runs 40% off every festival and the other has never dropped below $8.
Practical version that costs nothing: pick the 3-5 games closest to yours, and instead of eyeballing their price once, note three things. Base price, deepest discount in the last year, and how soon after launch the first big discount came (SteamDB shows all three for free). Then price against the discounted reality, not the sticker. It also tells you roughly when your own first sale should happen, so it becomes a plan instead of a panic response.
Full disclosure: I am currently validating a small watchlist-alerts tool in exactly this space, which is why I had these numbers in front of me this week. But the manual version above genuinely takes 20 minutes and answers most of the pricing-by-comparison question.