>>63919366
You're overcomplicating things. You're not gonna get any use out of a crappy overpriced dagger and that red dot isn't strictly necessary at the distances most defensive shootings take place at either.
Something reliable (though admittedly not super ergonomic) like a Glock 26 will set you back $550 at the most and you'll have plenty of money left over for a decent holster and a bit of ammo for a day at the range.