So, when I was a newbie, I lost tons of money on traders by buying and selling the goods on flea market. After a couple times, I realized that you actually can make money by buying from the flea and selling it to them! You will make money and gain that loyalty! (I am not sure if this was posted before, but I couldn't find anything on the web or particularly Reddit.) Hope you enjoy!
Other traders will be added!
For Therapist:
She loves overpaying you for most of the keys! (It works with multiple keys, if you look into it you definitely can find one.) Here is an example:
For Skier:
Skier will pay you a higher price for the PBS suppressor than the flea market. Night time prices will help a lot for this!
For Jaeger:
My far favorite for Jaeger is the knives. Small amount of profit, but profit is a profit. 🙂