The point is, you should ask someone how much they'd be willing to pay. Even nontarget customers will give you some sort of ballpark value that's better than guessing in a vacuum.
But of course, target customers are better. I have a feeling most people when starting out, don't even ask those, but just take the "expenses plus a bit of margin = price" formula.
I agree with second part being a pitfall, but re: ask someone/anyone, let me illustrate why this is problematic.
A friend of mine was starting a subscription ecommerce site targeted at women (clothing & makeup primarily). She asked me about pricing (I'm a guy) I used all my "knowledge" to offer up my thoughts on price and then she asked "would your wife or sister use it at that price?" and I couldn't say. At that moment, it became apparent to both of us that although my pricing logic seemed ok in a theoretical, consulting-esque way, I was actually a pretty useless windbag in this circumstance.
I fear asking non-customers just risks getting at very wrong pricing - garbage in, garbage out. And also risks you missing out on great product feedback as well.
But of course, target customers are better. I have a feeling most people when starting out, don't even ask those, but just take the "expenses plus a bit of margin = price" formula.