I'm sorry, but you have to find this changes by yourself. It's because we are simulating changes directed by traders AI. IRL they will do it without warning. They see demands, track shortages and make changes they need. Later we will add a feature – traders with send you messages about this upcoming changes, if you are in good rep with them, have good karma etc. That's the reason that we can't say about changes AFTER actual changes applied.
Additionally the reason we can't tell about changes BEFORE cause ppl who can go into the game quickly after the change note. They will stock up goods with old prices-traders and have the advantage to speculate on flea market. You have to understand this.
Of course it's not a perfect system but it is actually in a big test. So, sorry for inconvenience.
The good thing is that it's getting balanced in the way Tarkov should be experienced.
P.S. Item/weapon/gear parameters changes though need to be declared – I agree.