I think I paid $170.00 for the 4 windows and the hatch - tint was charcoal at 35% (our legal limit). This was just outside DC and installed 2 years ago, so I don't know what it would cost now.
The glass is tinted green to protect against UVA damage. I don't know how well it works, but I'm sure that adding a tint would help somewhat. With that slight facotry tint, you may be over the legal limit if you try to install tint *at* the limit like I did. If you get busted for this, I'd be impressed.
Good luck