Everything can be compared to the basic ( water - flour - milk - eggs - chicken )
If a chicken is 10$ and full roasted chicken is 12$ and a burger is 15$ you know it is a scam.
If 1 kg of flour is 2$ but a small piece of bread is 7$ you know it’s a scam…
Coffee is a good example, single origin roasted coffee beans with 300gm is 17$ you can get 15 cup of it. That’s rounds up to 1$ per coffee cup. If you the coffee in a store cost more than 2$ you know it’s a scam. But you can take into account other expenses ( staff - settings - experience) and decide based on that








I would suggest Send memes or funny images if you can. Sending messages might feel more stressful, they might think they need to answer. Images have no expectations of respond.
Even books or podcast things like " I know you like this topic, and when I saw this book I thought you might enjoy it "