Forget the Tauri - production quality too iffy.
You won't be getting a Sig near the $400 range.
S&W will be well over $400 too.
So, that leaves the Rugers... plus I would also suggest the Kahr CW line ($450 range) - GREAT VALUE for quality, reliability.
Whatever you decide, DON'T be tempted by low-priced minor manufacturer guns... In the long run it's always a mistake.