The average cost of a space shuttle mission was $450m. That's 8 astronauts and 23,000kg of payload. [0]

Soyuz costs $62.7m/seat. [1] Which means that 8 seats to the ISS on soyuz is actually more expensive than a shuttle launch.

I couldn't find how much non-astronaut Soyuz payloads cost.

SpaceX's Falcon 9 Full Thrust can lift almost as much payload as the Shuttle, at 22,800kg.

I'm not sure how much each Falcon 9 launch to the ISS costs. Maybe someone else can chime in?

0. https://en.wikipedia.org/wiki/Space_Shuttle_program

1. http://www.space.com/20897-nasa-russia-astronaut-launches-20...