It's a kind of ass backwards thought process and here's why.
The most used (inc by me) supps are:
Creatine (works fine and is cheap), Fish Oil, Vitamins, Joint Products (I notice this more when I DON'T use one) before we get into the extras. Now with all of these ($100 max) do not expect crazy results. Many do. Fish oils and vitamins are, as much as anything, like insurance. Protein powders and the like is just food. And actual food is better.
If you get into the silly pre-workouts (all claiming to be crazy strong) and hope to have epic workouts in a drug like state then they are 100% a waste of money. Just have a cheap coffee.
If you get into, esp post cycle, a test booster or an organ protector (like N2Generate or N2Guard) then hold their prices up against the cost of the cycle. Then they ARE worth the money. But you don't have to use them year round.
I think it's what is implied in advertizing that's the issue. Putting up a professional athlete and making you think you'll look like that if you use product X... that's why you'll question $100-200 a month.
Anything else is mostly trial and error.