Idk. . .

Should i use 100 souls in the shop? Im Lvl 57, im wearing 3 Epic, 1 Rare, 1 Legendary and 1 Unique

If you only have less than 300 souls then 10 soul purchase will do so you can have multiple chances to draw. A 100 souls purchase is risky but very rewarding when you're in luck. Do this if you have lots of souls to dispose.
lazyboi
If you only have less than 300 souls then 10 soul purchase will do so you can have multiple chances ...
Amazing !!
Hey hey, you're too lucky and it's not a reference!
あきる/AkiRu
Amazing !! Hey hey, you're too lucky and it's not a reference!
Hehe not always. It happened to me twice or thrice as I remember that I get 3 uniques in 1 draw. Last one was last year and it happened when I didn't buy anything for months. Several times it was only 2 uniques. But majority of my purchase was blank and I remember a time I used 500 souls and all I got was 1 unique amulet. Surely the shop is unpredictable.