Depends what you're looking for... and how much you're willing to spend.
If you are looking for a WW2 beware that they have been known to break lock blocks and crack slides,
so I wouldn't recommend getting a nice one if you plan to shoot it.
A decent mis-matched WW2 shooter can be had for $500 or so with some patience.
A post-war P1 or P38 should run about the same.
Correct matched WW2 will run more and like anything else condition, original / matched parts and no import markings drive the boat.
You need to be on the ball to get a good deal at a show;
if you're looking at WW2 I'd recommend going to the P38 forum with a want to buy ad, or a good dealer that specializes in them.
Now that you have C&R in hand the world is your oyster.
Well, most of the US is anyway.
His point on the WW II ones is valid. I got a chromed one to shoot simply because it was cheap, in good shooting condition, and something I wouldn't mind repairing if it took damage. All-matching AC 43 Walther. If you want a safe queen, buy the one you like but be prepared to pay dearly. If you want a shooter a P-1 or a mismatched/refinished/chromed P-38 is the way to go.