>>279791584
I didn't actually know what "C.O.D." stood for. I might've googled it when I first read this chapter. In Japanese, he said "着払いでな!!" instead, which does in fact also mean "cash on delivery". It refers to being charged when the package arrives rather than prior.

Also, I have a note from Furinkan: "Rinne says he is frightened that the package might be part of a scam (悪宅商法/akutokushouhou)." 悪宅商法 can apparently be translated as "unethical home selling practices".