Just to throw out an extreme example, I definitely wouldn't hire a wedding photographer who charges $100 for a day's worth of photography. If they have to charge that little, they probably aren't very good. And given the importance of the occasion, I want to be sure that the photos are excellent.

Pricing and adoption aren't a linear relationship, because price points also position products.

I don't know how big an effect this is in the $1-$5 range, but it extremely important in premium categories.

$5 laser eye surgery, $10 car price communicates value.