The pulling rate is pure luck but if you want some example...
Good one.
There is illustrator name shuz(しゅーじ) that draw some charector in FKG.
He (or maybe she) do 10 eleven pull to get 6* Lantana Flower Festa ver.
He (she) also got 6* Fresia from salt ticket before got Lantana.
You can see his (her) historical pull on his (her) twitter.
Bad one.
There is a guy name Wasma something in my native DMM FKG community.
He want Kurukuma (6* piercing) badly so he throw 950 gems as fee to summon her.
Result... he lose all gems in vain.
But at the end of the day we have to pull to do our very first squad.
So just pull it.
PS. On DMM version there is some kind of compensation system if you success pull a dupe girl.
They'll give rainbow coin for your dupe pull. But I didn't peak into this system yet.
So can't tell how that coin work.