I have never player demons souls or dark souls. Should I get into it at this price and for this edition?
This "Prepare To Edition" is the only edition of Dark Souls on the PC (currently).
And *this* edition includes the $15 Artorias of the Abyss DLC with it (that console gamers have to actually pay for).
You definitely NEED the DSFix Mod (see the link Argyle linked) so you can boost the games' graphics settings/quality (SSAO settings, AA, DOF, etc) and unlock the resolution (it's stuck in 1024x768, IIRC by default - you can really boost it up w/ DSFix). For example - I have it w/ DSFix set on 1980x1020.
You definitely NEED a controller to play this game. It's very clunky w/ a KB+mouse - and obviously this game was NOT built for that. This is a console game ported to the PC - and it shows, in the controls regard.
The game's combat is amazing and as precise as can be. IMHO, the game itself is downright hard & brutal - so, hardcore gamers should only apply. Think like NES-hard. If you easily rage-quit games and don't come back, this game might not be for you. But, do know this - when you finally get a victory over an enemy driving you crazy, mini-boss, demon, or boss - it's the best feeling in the world! You feel like you actually accomplished something.
The funny thing is: it's a game that punishes you a lot, when you make mistakes and fail, but you might keep coming back for more. Here's why: when you die, you lose your souls - and it dangles that carrot (of Souls) so you want to go back to where you died and go get your Souls back. The thing is: when you reach a Bonfire, most enemies flat-out respawn within the area - so, you can try to grind your way a bit to try to redo areas over and over to try to make success a bit easier for you (whether upgrading weapons, leveling up, ascending weapons, etc etc)...
EDIT:
I should warn you - the game requires both Steam (For install/playing) and G4WL (to play online, if you so choose to).