So i just grabbed this. I have been making impulse purchases lately, this game actually seems kind of awesome, and its 75% off so it was only 7$
If you find yourself really enjoying the game you might consider picking up Back to Ubersreik while it's on sale because it comes with a weapon for each character and 3 decent maps (which wont have any nostalgia factor for you if you didn't play the original).
Winds of Magic also comes with a weapon for each character, but it only comes with one kinda shitty map and a game mode that NOBODY likes or plays, and is twice the cost of BtU.
Shadows over Bogenhafen is two ok maps and a bunch of weapon skins (purely cosmetic), but no new weapons.
The Grail Knight career is a premium career for Kruber that comes with a weapon that all his careers can use and a weapon that only his GK career can use. The cosmetic stuff is locked behind a separate DLC 'upgrade'
The Outcast Engineer career is a premium career for Bardin that comes with two weapons all of his careers can use (slayer cant use pistols obv), same deal with the cosmetics
That's it for stuff that's discounted.
The Forgotten Relics pack is a weapon for each character, none of which are bad, although some are a little niche.
The Sister of the Thorns is a premium career for Kerillian much like the others, 1 SoT only weapon, 1 weapon all her careers can use, cosmetics locked behind a second purchase.