Price a new product

Suggest three prices — low, fair, premium — for [strawberry jam] in 300 g jars, with one sentence of reasoning each. Facts: ingredients cost me [€1.40] per jar, I spend [20 minutes] on each, I sell at a weekend market. Then list the 3 things the label must show for the premium price to be accepted. No marketing words. Start with the result itself — no introduction, no summary at the end.