1 ref costs about 0.33euro and you even dont have any weapons to make scrap

You can trade, but only items you've received from others.
You can try for that by means of tf2r.com, but yeah, premium is the way to go.

Myself, I've been buying a few games @ 1 tf2 key = $1.50 (note the dollar price differs from others, but is general measurement of value), while giving a bit extra to sweeten, but it's a though market. I generally hope for cheap legit sellers on tf2outpost (always consider chargeback risks)

You can buy an item for $0.49 and get Premium... but the money comes from your Steam Wallet and can only be added in $5 increments (Replace $ with your currency).
Not sure about the trading aspect of non-premium members. I know they can RECEIVE items in trade, but I know the items you gain from weekly drops and/or promos (i.e. the B.M.O.C. from last Christmas) are untradable until you go premium.

Its like a casual-shooter with cartoony-graphics and somewhat of a loot-system with useless Hats... thats all I need to know.
Sometimes I see people buying Games just because of some of these TF2-Items they get for it. Thats soooo stupid. I wouldn't even play it for free ....oh wait :P

He's also a self-important douchebag who thinks he knows everything and gives out horrible advice.