The trick that worked for me was cutting down on unnecessary back-and-forth. Before I ask anything, I spend a minute really thinking about what I need and write it out clearly in one go. Saved me from a bunch of replies that just waste tokens. For their bigger enterprise clients they probably get bulk discounts too, so the per-conversation cost is way lower than what we see.
Yeah I actually read somewhere that their user acquisition costs are like triple what they were a year ago. Not sure how long you can keep that up before investors start getting nervous.