I work with a guy who's dad was a paratrooper in WWII with the 101st Airborne. after hearing stories of this luger his dad brought back I told him to check the serial numbers. He said they all match even the magazines! It also has a cleaning kit and holster! Bad thing is that the guy hardly knows what he has. What you guys think Its worth?

$1,000-$2,500 depending on condition and markings.

Lots of serial numbers, even internal numbers that need ot be checked.  IF it is truly all matching including the magazines(2) then i think the price is much closer to the $2,500 than the $1,000, ecspecially since it is a WW2 pistol.  When i was shopping, the WW2 always brought a premium over the WW1 models, and i would even in my limited knowledge venture to say that the $2,500 would be a safe bet, and think that at auction could bring over 3K almost 4 maybe?   But i'm sure the experts will be along shortly.

Umm that depends on the code, rarity, originality, finish etc more than anything else and without pictures we cannot make any guess on value. It could be anything from a $800 shooter grade common code DWM 7.65 Luger to an all Matching police C marked or special contract variation I have no seen many lugers go over $1500 lately that SELLS even if they are all matching down to the firing pin. I got my last matching S/42 with holster at local gunshow and it has been sitting on table for $1200 with no takers for quite awhile.

Jeez, I gotta go where you are. Nice WW2 lugers here seem to start at around $1800 and rise up to $2800 with matching mags. $1200 gets you a crusty one, mix matched shooters $800-$900.
I know, 'cause I've been looking for a nice 97%+ '36-'39 S/42 lately without luck in my budget range.

From $1500-$15,000. It all depends on the condition and manufacturer. Say it happens to be a run of the mill 42 code, then you look at the low side in average condition. But now it turns out to be a navy or Krieghoff, then you go to the high side +.