We can build a 100,000 ton nuclear powered aircraft carrier for around $5 billion, and a nuclear powered seawolf attack sub for around $1.5 billion. Could a 1,000 ton space station with a crew of 8-12 be built for the same price?

Most of the station's weight would be taken up by frame with maybe 15-20% for the actual crew modules. Such a station (similiar to the dual keel concept) in an equatorial orbit would be of great use for assembling interplanetary space craft. For me the main purpose of a space station would be in the following order.

1. A ship yard for the assembly of interplanetary craft.

2. A port for those same ships, as they would be unable to land on Earth.

3. A test bed for new technologies concernig space exploration, such as propulsion, life support, power generation, etc.

4. A lab to test the effects of long duration space exposure on people.

Forget about growing crystals or other 8th grade science. A space station should be a stepping stone, not an end unto itself.