How may Icompare equipment that I want to buy from traders with the equipment that I am "wearing"?

Hello.
Example of what I mean :
I go to an armour trader and I consult his wares. I intend to buy a helmet to replace the one I’m wearing.
In the trading screens, I can see the specs of what he’s selling : protection, weight, price, etc.
My “problem” is that, unless I have a super memory - which I don’t - I can’t easily compare what he is selling to what I am already wearing.
I can’t hover the mouse over my current helmet to see its’ specs.
That means that I have to note down the info of what is being sold, leave the trade window, open my inventory screen, note down the info of my currently worn helmet, reopen the trade window and, only after having done all that, I can see if the new helmet is worth buying - phew !
Does anybody know of an easier way to compare specs whilst trading ?
Thanks.

You can inspect the item equipped in the “sale” window. (Usually you can sell to people who offer a type for sale).

You can see at a glance what improves or reduces “as equipped” stats by blue/red highlighting of the summary data. Note though that for charisma and defence this includes dirt and damage “as equipped”.

Fully repair your items. If you click at an item from a vendor now, the numbers of your armor and stats to the right should turn blue or red. Blue = better than currently equipped, red, worse than currently equipped