The test I use, and it has held up: would I be comfortable if a customer bought the expensive plan?
If the answer is yes — it is a real plan, it delivers real value, some customers genuinely want it and are well served — then the tier is honest and its effect on the perception of the others is a side effect of existing.
If the answer is "nobody should ever buy that", you have built a prop. Sooner or later somebody will buy it, because somebody always does, and you will have taken money for something you designed to be a bad deal.
That one question separates almost every real case I have seen, and it does not require deciding anything about psychology.