Can private-sector space business be profitable, or is it just an exciting way for billionaires to live out their fantasies?

Here’s the first estimate for how much companies will save when buying a ticket on one of Elon Musk’s lightly-used SpaceX rockets: A cool 30%, resulting in a launch cost of $40 million.

That might not sound like a deal, but consider the competition: SpaceX’s US rival ULA charges a minimum of $164 million per launch, and Arianespace, the European space company, charges clients about €150 million ($167 million) per launch, though pressure from SpaceX may cut the cost of its next generation rocket to €90 million.

Reusability has always underpinned SpaceX’s goal to provide the cheapest access to space, ever since Musk couldn’t find an affordable rocket to send a greenhouse to Mars.

Gwynne Shotwell, SpaceX’s operations chief, discussed the price reduction at a satellite industry conference yesterday. After landing the first stage of a Falcon 9 rocket in December, SpaceX estimates it could prepare it for flight and re-fuel it for just $4 million, slashing about $18 million from the rocket’s cost.

The company doesn’t currently plan to reuse the smaller second stage of the rocket, which delivers satellites or space capsules to the right orbit after the first stage has propelled it into space.

Next, SpaceX will have to actually re-fly a rocket that has been to orbit and back. Blue Origin re-flew a previously used sub-orbital rocket earlier this year, but the speeds and stresses of orbital flight are significantly greater. SpaceX doesn’t plan to fly the stage it landed in December again, though it did test-fire the engine successfully without any extensive refurbishing.

“You pull off the cover and that wire harness is pristine,” Shotwell said, according to Space News. “The metal is still shiny. You pull off the thermal protection system that we have near the engine, and that engine is beautiful. It is perfectly clean.”

SES, the leading European satellite company, has said that it wants to be the first company to re-use a Falcon 9, though the company’s CEO Kari Michel Sabbagh said he wanted a 50% price cut to inaugurate the system.

SES has been a booster of SpaceX as it develops new technology; its SES-9 satellite was launched on March 4 after several days of delays while the company figured out how to load its new super chilled liquid oxygen tanks.