B&H Photo has a few things for the EOS R system in their used department. All of the pricing seems to take into consideration the recent instant rebates from Canon USA.
Used Gear in Stock at B&H Photo
Canon EOS R6 Body $2123
Canon EOS R5 C Body $4078
Canon EOS R5 C w/RF 24-105mm f/4L IS USM $5189
Canon RF 15-35mm f/2.8L IS USM $1838...