yup, eotech and aimpoint would be my suggestions too. they are the top of the line brands IMO, but their standard models are still quite affordable.
I paid $420 for my eotech 512 brand new. its true laser holographic, completely parallax free, and battery life is 600hours-1000hours. it comes with an allen screw and a thumbscrew, so the choice is yours of which to use.
keep in mind, any other red-dot sight will be lucky if it gets over 2 hours of battery life. strongly factor that fact into your decision. also remember that when replacing the battery in a lot of sights, it alters the positioning, drastically throwing off the aim. eotech's are NOT affected by replacing the battery.
eotechs are also one of the only ones that are genuinely waterproof. nearly anything else will just fizzle out at the first trace of liquid water.