Eh... well yes CS is not cheap but also... CS is Mouser. They got acquired 7 years ago https://www.crowdsupply.com/announcements/crowd-supply-has-b... .

You can buy the exact same products if they have enough in stock on either platform so price should be about the same e.g. https://www.crowdsupply.com/mouser-electronics and the opposite https://eu.mouser.com/manufacturer/crowd-supply/

They might have big margins on generic products but nothing obvious to me. FWIW bought uSDR with antennas just last month.

Ah... good to know... I don't have anything to shop for right now, but if they're the same, I'll just go to the source.

Well the "source" is arguable. If you want stock parts it's definitely Mouser (or their suppliers) but if you want a project, namely something new made out of parts provided by Mouser then it's still CrowdSupply. I didn't take the time to compare but I imagine prices are roughly comparable and maybe you get projects slightly faster on CS, I'd hope so at least. You definitely get to follow the evolution of the project though, which is positive (your learn how it goes) and negative (you can get frustrated by delays).