<< I can't see having a tiny weapon like a Walther PPK as a sole handgun - the .380 is a rather marginal round, and this gun is really specialized to concealed carry.
I also find it odd that AmusedOne is saying he would "never" own a Glock or 1911 - these are probably the two best-developed combat handguns in the world, and are as safe as anything out there. I actually think both are considerably better for self-defense than any DA/SA gun, which will have drastically different trigger pulls between the first and second shots. Some combat handgun coaches even train students to deliberately throw the first bullet into a safe area away from the target for this reason(!) The main reason the DA/SA pistols came into existence in the first place is one related to public relations - the "cocked and locked" 1911 looks scary to the layperson who is not familiar with firearm operation, since the hammer is back and the gun appears to be ready to fire.
The best solution IMO is to go to a range and fire a variety of different guns to see what you like. As a first handgun, 9mm is probably the most desirable caliber in that it is very inexpensive to shoot, generates little recoil, and is reasonably effective as a self-defense round. The widest variety of guns are chambered in 9mm. Personally I prefer .45, which is somewhat more accurate and has much greater power, but I would still start with 9mm.
In your price range, I would consider a used Glock or other quality 9mm handgun. The Berettas are very decent (though I find the standard-bearer 92FS way too large and heavy for what it is), and are often available for around $400 new. The Springfield Armory XD pistols are also pretty inexpensive, high-quality, and loaded with features for the money.
Personally I like the Glock 17 (I have big hands), but the compact Glocks are better for many people. Glocks are by far the toughest handguns made in the world, and since it is nearly impossible to wear one out (Chuck Taylor has shot a Glock 17 more than 300,000 times, as well as burying it in soil and manure, freezing it in ice, and attaching it to a salt-water buoy for six months, and it still shoots perfectly), you may as well buy a used one. The Glock design is not by any means inherently unsafe (it is the choice of a vast number of police departments and military agencies around the world), but it does require a shooter who is disciplined enough not to put his finger on the trigger until he is ready to shoot. >>
No, no, no. I would never CC a Glock. I think they'd be fine combat HGs, just not for CC or for inexperienced gun owners. They're just too easy to fire.
Sorry, but that's just my opinion.