hi @abigail04 thank you for sharing a story from your life in The Ink Well. How fortuitous that you managed to find a cheaper source of stock. That must have been quite the internal struggle to overcome your lack of trust in someone new. I happen to think you were wise in being cautious, as sadly not everyone in the world has good intentions.
A couple of pointers:
Your writing would flow better if you used a grammar checker like Google docs to check and edit your grammar and punctuation before you publish. Some sentences are confusing due to the lack of punctuation. eg:
A customer who has been consistent in buying goods from me and even on credit sometimes happens to have a brother in a town very close to the border where goods are sold at a lower price than here.
The above would flow better and remove ambiguity as to whether the word sometimes belongs with buying credit. or the brother. In the latter situation it would make no sense, but this reading is therefore jarring for the reader.
It should be rewritten like this:
A customer who has been consistent in buying goods from me, and even on credit sometimes, happens to have a brother in a town very close to the border where goods are sold at a lower price than here.
Then:
The way he answered made me nervous.
You tell us that the way he answered made you nervous, but as a storyteller, you would do better to show us through dialogue and the senses. What did he say? How did he sound? How did it make you feel? What sensations did you have in your body? Check out this resource from The Ink Well on Show don't tell if you want to look at improving this aspect of your writing.