I think you have to remember that it is a business, and the primary goal is profit. With that in mind, I think you can become more resistant to the sales pitches.
I do think, though, it is good practice to "throw them a bone" and buy something once in awhile. Yes, you may have spent a ton of money on the program up front but as time passes, an occasional sale will remind them that you are customer who has invested in the program.
It's a give and take thing when you are dealing with a business.
Also, I have found it very helpful NOT to become too close to any counselors. Sure, I have preferences but I am following this program for me. I will not allow any kind of attachment to counselors undermine me. In that same line of thought, since I view the counselors as "business people", rather than friends, if some get particularly snarky (I think it happened once), I just don't let it bother me and it blows over.