Learn to physically react to any price. It takes some acting and some practice, but it’s actually kind of fun and boy, does it pay well.
Ask someone what the widget costs. Whatever they say, your response is, “What? You’re kidding me! That’s twice as much as I expected.” Often, that’s all it takes.
The guy will drop his price or throw in something extra. At the worst, he knows you are “sensitive” to price.
Warning: Tell your spouse what is going to happen. Once I flinched at a price, and my girlfriend at the time said, “I got so nervous when you did that. I could never do that.” I had to explain it was all an act. Practice your flinch.