I would like to know what you think of mint & used stamps.

In Scott (USA) & Yvert & Tellier (French) catalogue both mint & used
stamps have the same value, ( more recent ones from 1980 to nowadays)
& in Stanley Gibbons, it is the contrary, that is recent used stamps
have more value than mint (in general)

Could you tell me what is your opinion about it? I am using as
example Mauritius stamps, it may be different for other countries.

Do you consider that used recent stamps ( from the past 30 years or
so) are more valuable than mint ones or not?

Are you willing to purchase used stamps at higher than what you
normally accept for mint stamps for your collection?