Yeah, I see what you're saying. When I first started I wondered why cutting is allowed, and if it wouldn't just ruin the margin, but really if you just use a bit of logic, margins can still be updated properly based on those reports.
Here on this guide: https://flipchat1fc.forumotion.com/t40-how-to-pricecheck-as-a-pc-er
Me paraphrasing it:
Let’s say pc’er said AH: 4000-4500
For cuts bigger than 75k
Example scenario:
Player: AH Sold 4400 ~2 mins
That wouldn’t influence the margin as it’s a cut of 100k
Cuts bigger than 75k doesn’t affect the margins if buy price/sell price is lower than 15 minutes
NB: This applies only when rule isn’t applied, and a person just uc (undercuts) unnecessarily
How to handle cuts:
Player: AH buy 4033 ~15 minutes
Margin would change from 4000-4500 to 4025-4500 (closest rounded down number)
Tl;dr if a person cuts (didn’t apply rule) and it buys/sell in less than 15 min, doesn’t affect margin
If it does you can change to that price, thus margins aren’t affected at all
When it takes over 15 minutes to buy at a margin that was uc, it’s saying that it wouldn’t buy/sell at a margin that’s not uc, thus why you would update it.
If it’s less than 15 minutes and person uc, margin stays, that’s all (because it would still buy/sell at the margin that wasn't uc)
Otherwise when a person doesn’t cut and applies 25k/30 minute rule, regular updating rules take place!