Heres the thing: Ive seen too much people just never checking their bids enough.
I own Swedish-Norwegian Kingdoms and I have seen way too many "steals" of cards that are worth WAY MORE than their ask.
For example the United Missourtama States (correct me if I'm wrong). I bought that thing with an ask of 1.00 bank while it was worth 15.00 bank. Mostly nobody checks their bids.
So here's the suggestion: A notice/notification that reads "NATION has outbid you on NATION card" or something better. It's pretty simple too.