Yes, exactly. A lot depends on your expected volume. Essentially, masks are your fixed tooling cost for chips. You then amortize that over your full volume. It’s easier to justify another mask set to fix bugs if you are going to be selling oodles of chips and the cost ends up being negligible and much harder to justify it if the volume is low. Years ago, I was CTO at a startup when our chips came back from fab. Everything looked good except for a silly error that our chief architect had made. He felt horrible for a couple weeks. He was a great architect (meticulous and precise) and I kept telling him that it was no use crying over spilled milk. Engineering is hard. But there went another few million dollars of precious venture capital up in smoke for the replacement mask sets.

Most chips have basically one revision after first tapeout, because it's hard to get everything right first time. Small revisions can sometimes be done in the metal layer only, which is cheaper.