Same set

1:1 + 10 Gems or any card, background, emoticon, etc...

Different set

1:X Good offer

https://steamproxy.net/tradeoffer/new/?partner=118434660&token=Yv9i8aNT



PS
If I have multiple cards, it doesn't mean I get rid of them easily - e.g. out of many: Final Fantasy's.

For me, good offer still means 1:2 value.
Steam mobile authenticator is preferred.
Your inventory set to public is preferred.