Hi there, it's always me.
When I saw around decorations for great helms I thought that maybe I can attempt to create one (but well, not me but an adult person Very Happy ).

I immediatly fall in love with the idea of fixing two horns on my helm, put the president of my...mmmmhhhhh...well...reenactment group(?), said that in our period (1300-1355) adn in our area (North Italy, Friuli), the population was a little "poor" and "rough", so the knights or heavy infantrymen (like me), couldn't afford to a decoration of theyr helm.

Is this right? what can I do? Help please .

Well the horns and similar deccorations appear to be used mainly during the tournaments - they offer no benefit whatsoever during the battle and are easilly damaged so I doubt you would want to go into battle with gilded horns on the helmet. And infantryman proably woudl not have anything like that on the helmet at all...

Well, for decorations I don't mean only horns, but also other stuff, like leather or so.
Here is written that the decoration were used...
http://www.myArmoury.com/feature_spot_ghelm.html

I have seen the article of course. Still, having worn and used such helmet on numerous occasions I think that majoroty of the crests where not used in war, and almost compleatelly sure they where not used by footman.

I'd have to dig back through my research for all the specifics (which I don't have time to do at the moment), but I can address a couple of things.

There is period art of crested helms being used in battle.

Great helms seem to have been used mostly (if not exclusively) by the somewhat wealthy to very wealthy.

The majority (if not all) of the surviving great helms of the 13th and 14th century that I've seen have holes for attaching crests.