There's a quiet frustration baked into this question, and it's one we recognize well. The user isn't asking for complex macros or a crash course in financial modeling, they're asking for a simple, reliable way to preserve a number while another changes. That's not a spreadsheet problem; that's a logic problem. And the fact that Excel made it feel impossible isn't a failure of their understanding, it's a limitation of the tool they're using.
What they're describing is the need for a static reference point, a value that doesn't recalculate when the inputs shift. In traditional spreadsheets, that's awkward. You can copy and paste values, but that breaks the moment you want to rerun the scenario. You can use circular references, but that opens a can of worms. The real answer isn't in Excel's formula bar, it's in rethinking what a cell is supposed to do. An AI-native spreadsheet can treat that $500 not as a formula output but as a snapshot, a checkpoint you can compare against without losing the thread of your working numbers.
The practical takeaway here is that the user's instinct is sound. Holding a value in place to measure a delta is exactly how you should track tax differences, budget variances, or any before-and-after scenario. The problem is that legacy tools force you to choose between a live formula and a static number. You shouldn't have to make that choice. The solution is a system where you can lock a value, keep it current, and still see the gap clearly, without writing a single line of code or wrestling with conditional logic.
This isn't about abandoning spreadsheets or learning Python out of necessity. It's about recognizing that the tool should adapt to the way you think, not the other way around. If you're holding a number in your head while you change another cell, you're doing the work the software should be doing for you. The fix isn't more manual steps; it's a smarter foundation that lets you capture, compare, and move on. For anyone tracking tax differences, or any dynamic figure that needs a static baseline, the goal should be to spend your energy on the decision, not on the mechanics of preservation.