My question is, what is the difference between a $30-$40 Tasco red dot

http://www.opticsplanet.net/tasco-1x30-reddot.html

And a $350-$400 Eotech/Aimpoint dot dot scope?

Naturally people would probably say the Aimpoint/Eotech would last longer and hold zero better, not to mention better lenses and water/fog proof.  I am not convienced this would be entirely true.  So long as the Tasco held zero, I would think the scope should be pretty good.

I have looked though a $30 Tasco red dot and quite frankely, it looked very close to my $350 Aimpoints.  The Tasco even comes with it's own mount!  You can spend $100 for a mount for the Aimpoints/Eotechs

Who has alot of field experience that can chime in?