After the presentation they recorded a new no-crash version and uploaded that to YouTube as well. They wanted to risk the crashes during the presentation to show it was a live, playable demo
limitedduck
You have the option to buy most ships with real money, but the general cycle is about 6 months after release into the persistent universe the ships are purchasable with in-game money. The only reason to spend real money on SC is if you can't wait those 6 months, want to support development, or don't want to bother with in-game money for whatever reason. There are some exception ships though.
As for the detail, there are big differences between SC and ED. For one, SC ships have completely modeled interiors since the intended gameplay is for you to manually board your ship from outside. ED has no ship interiors as far as I know, just cockpits and exteriors, no matter how big the ship is. SC also has more ships than ED even excluding all the SC ship variants, ground vehicles, and ships that don't do Quantum jumps, the frame shift equivalent of ED.
I'm not comparing their scale, just the ability to enjoy something without it seeming like there's much there to others. But if you want to compare, I was imagining MC back before even the Nether. I had plenty of fun just mining and stacking blocks to build whatever, nothing like what became available toward 1.0. SC is kind of in the same situation, but their timeline is just 20x greater because of the scope.
The game being worked on now isn't really the same game that was originally backed. They essentially had to restart development a few years after the campaign because the scope had expanded. The tech at the time didn't cut it so they've spent most of the time since then creating new tech that would