While dentists are definitely quite important for the community because of the fact that they know how to make it so that people can trust them and get their dental health improved, you should also try to realize that in many cases dentists are going to be trying to earn more money from you. Hence, if your dentist tells you that you need to get invisalign put in then you should potentially take this with a pinch of salt. This is because of the fact that invisalign is actually fairly expensive, and a lot of dentists might get kickbacks for prescribing them.
What you should do here is ask around and see how much other dentists are charging for this sort of thing. The free market means that a lot of dentists have some wiggle room that allows them to offer certain discounts, and other dentists might take advantage of this to charge more than the market average in the hopes that this might lead to them earning a lot more profit that they can put towards making lifestyle improvements for themselves.
By looking into what invisalign offers you are doing yourself a favor since it benefits you in a lot of ways, but at the end of the day you should only be paying what’s truly fair and anything more than that is likely not going to be all that useful for you. By asking around you would be protecting yourself from dentists trying to make a profit, and you would likely come across some dentists or another who would be a lot more ethical and would only want to make your teeth healthier while charging prices that are extremely fair.