All told, I reckon 1000Kg of spacecraft deadweight plus 200-250Kg of supplies per astronaut is as low as you're going to get. So once you add your notional 85Kg astronaut, you're talking about 1500Kg at US $2300/Kg, or around US $4M per person for a ride into orbit. If you're really slick you might be able to shave that by 50%. 90%? I don't think so.
Done right, this will cut the cost of space tourism by nearly an order of magnitude and will open up the possibility of the private sector actually being able to send folks to do stuff in orbit -- like fix or upgrade comsats. But it's not a magic wand and it's not going to reduce the cost per person to orbit to the rough order of a year's salary for an engineer.