What is the best soul shop upgrade/s?

[Omega Man 5000]

Title ^

[Silberfuchs]

It's hard to say what's best, but the worst ones are those that are about confection (poop, confection, and larva).

Generally upgrades related to pets, cards and item rating are GOOD.
Clover is good as well, because you can never have to many expedition tokens.

The farming upgrades are pretty nice too, with healthy potato rewards being the weakest of all three farming upgrades.

[Dragon]

Just get them all:P
they keep adding more every few ascensions, so don't fall into the trap like i did and spend them on stuff you don't need like extra backpack upgrades.
There is also a Tier 2 version of each upgrade in soul shop page 2 that cost double in ascension 11/12? wish i saved for that one. (potato/skull/class exp upgrade 2nd tier changes to variable %gain based off of potato/skulls gained that ascension i think. Mine are around 2000% after 7days)
Soul points get easier once your auto whack time gets down to 5min intervals, your buff times around an hour, and your 10x 50souls daily is complete. Once they are capped out you should role a extra 5 points on the next auto wack until one falls off. it's not much but adds up is you trigger it 100+ times in a 24hour period. (i don't know how much i actually get for this but 100 triggers is a conservative estimate i think)

[marleau.martin]

residute, pet dommage and item rating are the 3 best
after that mil potatoes and skull are not bad
farming can be good if some left...but always have some in spare for when lv 2 or 3 of the best come

[Lowerdank xD]

"auto whack auto" gives you free 500 souls a day even at 15 minutes.. so that should be a pretty high prio to get early.

[Zeustiak]

There are also tier 3 shop upgrades. I don't know when they unlock, but maybe A15?

[Silberfuchs]

Originally posted by Zeustiak:

There are also tier 3 shop upgrades. I don't know when they unlock, but maybe A15?

Yes tier 3 is at ascension level 15, and tier 4 at ascension level 20.