I am also on the hunt for a new, better cartridge, and I expect to pay 2x or 3x more than the cost of my current cart. With that being said, I will only buy a cart that provides significant improvement.
When you state "It is only 1% improvement but it got you 33% of the remaining and it is a big deal to you.", I can agree that the logic (math) is correct, but I find the premise is wrong.
When a system improves from 97% to 98% , in your example, it is assumed that the SQ improvement will be audible and valuable . As many have noted in other strings, slight variations/improvements are hard to notice/remember even after a few days of listening. I expect most AGs will not spend an extra $5K (double) for a 1% improvement.
This is not meant to be argumentative, just objective. There are always new-folks looking for reliable, realistic insight and advice...