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.