Your gun looks like it's in very good condition. I would suggest checking out Simpson Ltd to get an idea of value. Also, you can send your gun into Simpson Ltd and have them appraise it. You would have to pay the shipping there and back, plus the appraisal fee, but it might be worth it. As Ameshawki said, P38 values are going up. Are the mags the correct, or are they aftermarket ones? Unless there's something about your gun that makes it unique I would venture to say it's worth about $1,000-1,500, but it could be worth more.
Some c&r stuff is going soft, but it really depends on what it is. I think a lot of what I call the peripheral c&r stuff, guns that aren't directly related to ww1 or ww2 aren't selling like they used to. Part of it is probably due to people buying modern guns, ammo and gear, and the other part is probably inflation is starting to have an effect.
ETA: Just noticed your serial number has no letter suffix, which should mean your gun was in the 1st batch of 10,000 guns made in 1945. Typically the guns were made in 10k units with the 1st batch had a 4 digit sn#, the the next batch would have the letter a at the end, then b, and so on.
Example: 1st batch 0001-9999, 2nd batch 0001a-9999a, 3rd 0001b-9999b, etc.
This could mean more value for your gun. Hopefully someone else can chime in. You can also ask about it on the
Gunboards or
Luger Forums