Yeah, it's totally possible to pay up for nutrients and spend WAY too much. But that's a grower's fault. When you do your homework, you will find out what should work for your grow and your goals.
I have to say, I sort of laugh when people talk about getting ripped off. Um, no one MAKES you buy anything. IN the end, it's your choice what you buy and what you don't buy. If you haven't done your homework, I think you should pay too much a few times.
Think of it as a learning experience.
IMHO, I don't think you need to have hundreds of products in your grow room. I have less than 10 and it works for me. I would have to have twenty or more, like it sounds like some folks try out.
I mean, really, if you're crazy enough to try out those complicated regimens, then you should be hurting from it. Your plants don't need THAT much. It's like eating everything in your refrigerator at once because you want to meet your nutritional needs in one day.
Your plants don't need it all - and your grow doesn't need it all.
Stick to trying out one new product at a time, see what your results are, and then add more if you want. And if you don't, don't.
No one's making anyone buy anything or use anything. We're all adults here (well, most of us...LOL)