I’ll gladly pay you in 100,000 years for a space hamburger today.
Fuel and transport cost money, so even if Proxima Centauri is having a sale on Unobtainium for $1/pound, when you include shipping the cost will be $100,000,000,001.
I don't think interstellar commerce would work like that. The reason is that you don't wait 50 years for the next delivery. You have a ship launch every year and pretty soon your delivery time frames are annual. Yes, there's a big jump for the first batch but after that the time frame dwindles. There is always the option of a lost ship or goods exposed to space, but then you would only ship the most durable items anyway.
Without inter-dimensional travel, there is no possible way to conduct commerce with other star systems, let alone other galaxies.
You need to able to go from one point to another and back within a reasonable amount of time.
Higher dimensions allow virtual instant travel time between two points. I’m sure some brainiac will find the secrete in the future.
Interesting article. It mentions mining asteroids. Think that would have a quicker return on investment. Few if any of the technologies discussed exist yet, but they’re not far off. At least not in terms of a civilization. His math seems solid.
That, or we could just invent a warp drive. This is not entirely snark. I know at least two people who are seriously working on the physics behind actually doing so. The trick is that while matter or energy cannot move faster than the speed of light, space itself can.