man i think there is no ban chance if you buy rare items that not special offer like aerinal or horn tera suul.
Well, we hackers have to stick together, in this case I'm trying to save your ass.
Believe me, the staff knew if you have bought a certain rare item in events that are already over. Stuff such as golden dragonslayer for guardians when you are a free player catches the admin's eyes sooner or later.
At first bro your example is different situation ! of course they can see it if you buy guardian items to your character which is no guardian.(exactly they wont but someone can report to mods :P )
And yes they can check my item buying history but nobody report me for this reason if they dont know i am using that hack.its absolutely not understandable..
Game stafss no time to check accounts one by one! Just be sure nobody report you staffs privately.
Dont be a victim of someof jealous peoples thats all^^