I've been searching too. There is a stable of good midsize to conceal well under the $500 ceiling. I have had handguns in years past, but none in quite some time. This time I have to consider my wife wanting to get one, so I have spent a good deal of time researching. For the money in the $500-$600 range, I personally am a die hard Beretta model 92 fan. That was my favorite I ever owned. For dependability and accuracy, it never fails and being on the heavy side, shoots like butter with low recoil. they have a slightly smaller compact 92 that has my attention.
For the others I have done research on, the Bersa Thunder 380 is very popular and highly rated, and inexpensive. It's in my top 3 to decide on. Other affordable compact models in the $200-$350 range that were appealing to me so far is SCCY, Taurus G2C, Canik, S&W SDVE. These are all 380 or 9mm.
I have not ruled out a .22. For home defense, this is a good option. As well as for cost of ammo. Well placed shots are highly important, and .22's can be very effective inside the home.
I've put a lot of time into researching, and as noted above, don't buy what you haven't shot. What looks cool or appealing, you may not like after you buy and shoot. Case in point, my step son has one of those palm sized Ruger 380's. I shot it. Hate it. Had I not shot his, that pistol would still be on my list. I'll drum up my list I had going and come back and post it. because of other commitments I'm paying right now, we just haven't bought yet. Had I got taxes back instead of paying, we probably would have gone and let her shoot accouple and purchased by now.