The thinest pistol I have is a Bersa .380--comes in different finishes, all in the $250 to $350 range. Mine has been very reliable and accurate, plus I like the manual safety. SIG 232 is similar size without the safety or slide lock. Of course neither is ever as totally reliable as a revolver, but they give you 8 rounds of .380...
I used to have 1 and regrettably had to sell it when i was fighting to get my disability. Mine was reliable and accurate enough for it's purpose. It was about the same size/weight as the Ruger LCP I have now. It did have fairly stiff recoil as one would expect from such a light small gun. If you can afford it go for it.
Sometimes you earthlings REALLY amaze me!
I dont want to be "that guy" but I have a glock 26 and love it. I have the pinky extention and can fit my big claws on it. Even better get the glock 27 and you can buy a lone wolf conv barrel for 100 and have 9mm and .40.