I'm seriously giving thought to buying a heavier caliber pistol for both home protection and concealed carry. The models I'm considering are;
Taurus 24/7 Pro
Taurus Millenium Pro
The new Kel Tec PF9
Ruger SR9 Compact
There may be a few others as I keep looking but what's everyones opinions on these so far? Being a disabled vet, on a pension, price is very much a factor. I'm looking at either 9mm or a .40 and not too large a frame. I want something to partner with my Kel Tec P32 and my over under 9mm derringer.
OK, I'll bite.
You have a KelTec P32 in .32 Auto and a O/U 9mm derringer, and are wanting "...a heavier caliber pistol for both home protection and concealed carry..."
I assume you are really saying that you feel that your P32 feels too underpowered and your derringer has too few rounds of 9mm. There are derringers in larger calibers, but if number of rounds of ammo is an issue that adds a whole new dimension to things. It appears that you want at least 7 or so rounds of 9mm or better in a single handgun. You also indicate that cost is very important to you. All of the choices you are considering are semi-auto's, with the exception of a .327 Mag revolver you have looked at.
I would suggest that you ask yourself a couple of questions and focus on how much and how you want to concealed carry the new handgun. If you want to pocket carry or deep concealment, then the only firearms you have identified would be the PF-9 and a snubnosed .327 Mag. If you would carry IWB, then you can handle a larger firearm which would include any you have identified. From what I know finding .327 Mag ammo is a problem, so that points toward the KelTec PF-9, if you want deep concealment.
On the other hand, if you would do an IWB concealed carry, then you should probably ask yourself if you want a "range gun" that can also be concealable or you really want a concealed carry self defense only handgun, as they can be different. For a range gun and doing target practice, I want good sights, longer barrel, single action trigger or at least SA/DA action, and a smooth short trigger pull of moderate pounds. This is absolutely not a KelTec PF-9 in DA only with a short sight radius and relatively huge trigger pull. Good sights often snag on holsters and clothes while drawing the weapon as do hammers, so that should influence your decision.
To me the key to answering your question on which firearm is how concealable do you want the handgun and how would you carry it when your are using if for concealed carry. Then ask how many range gun features you want.
Home protection is a whole other kettle of fish and quickly boils down to "how serious a home protection weapon do you want?" Questions regarding handgun night sights, caliber over penetration through walls, and wouldn't you really be better off with a cheap used 12 gauge pump action shotgun quickly come to mind.
Good luck. I think you really probably know pretty much what you want, but haven't asked yourself the right questions yet.