Now see, Mikey doesn't particularly care for them and I think they are really neat pistols so you'll get both sides of the argument here. Also, the write-up in the Shotgun News Mikey was referring to was on the Astra 400's, not the 600's.
There were at least 4 variants of the Astra 600. The first 500 were trials units, used by the Germans to determine whether or not to place an order for them with the Spanish. I have never seen one of these 500 trial units nor have I ever heard of anyone owning one.
The Germans liked the Astra 600 well enough to place an initial order for 10,000 pistols. These were in the serial number range of 501-10,500, delivered to the Germans and stamped with German waffenamts. Due to their scarcity and Nazi history, these guns will go for anywhere from $700-$1,000, depending on condition. I bought one last year for $650 and was proud to get it for that price.
A second pre-paid order for over 40,000 pistols followed and Astra manufactured them, but the Allies invaded Europe and the Spanish were unable to actually deliver the guns to the Germans. These so-called "Second Contract" pistols were never stamped with any Nazi markings or waffenamts. After the war the Spanish government sold the unused 600's to the newly formed West German Police (so the Germans paid for them twice). All the WW2 guns were manufactured in 1943, hence the 600/43 designation.
In the 1950's and 1960's all of the leftover inventory of Astra 600 parts were assembled into working guns and sold to various countries and agencies around the world.
Used to be the Second Contract and post-war builds could be had for $200 all day long as Mikey suggested but I see them going these for more in the $300-$400 range these days depending on condition. $250 might be a fair price for a family deal. They are slowly gaining popularity as an unusual pistol, I think.
The 600's are blowback operated, and some say this makes them recoil harder, but I really can't tell much difference. In any event, they are a well-made quality weapon. Your Dad could do a lot worse than an Astra 600. They are compact, reasonably accurate, reliable, and unique. What's not to like?
-Lee