I dunno ... standard Rugers MKIII's go for $260 new from retail places, and the 22/45s go for $245. You might be able to get a well-used one for about $150. And a Ruger .22 with 10,000 rounds through it is still 10X the gun that these SNS mini .22s are.
Then again, you did say "small," and I don't know if a 3" Ruger would be small enough for you.
But really, keep in mind that, while I've heard people who really like the small Berettas, for the most part all the mini .22s have serious reliability problems, and the Rugers and Buckmarks are probably the only reasonably priced .22 autoloaders I'd trust. Revolvers of course are very reliable and there are some very small .22 revolvers ... although I don't know if the NAAs are practical, and a S&W 317 is about $500.
If we're talking about something very small for defense, I would seriously recommend you look into something like a Kel-Tec that's actually chambered for a round that's meant for autoloaders. I'm not trying to debate the stopping power of a .22, I'm simply talking about reliability of rimfire ammo in autoloaders.