Idleon Guides
Down Below you can check worlds category for guides.
Gem Shop Tier List
Down Below is photo of Items that is recommended to you buy in ROW to maximize value of gems!
You still can skip some gem shop priority but you will lose chance to boost yourself faster and better.

Tier S - This category is very well known for most important stuff to spend on. Golden anvil , 3d printer , more card slots and etc. You MUST HAVE WHOLE category before even trying to spend money for lower tier category of gem shop stuff.
Tier A - After you got All S Category I can tell you getting Garden plants and Mushroom Familliar will help you alot with skills goes more smooth than before , If you buying Ruby Cardifier please atleast use it on very important cards such as Skill Efficency like a Troll Boss. More info soon here when it's done.
Tier B - More printer slots , getting sneaking pristines are insanely good due you can't get duplicates , others are pretty simple to understand.
Tier C - Reason why this tier have this upgrades and gambling stuff is cause it's not there perma progress , you have to be lucky to get something good ( Im talking about Chips ) Other stuff are kinda ok.
Tier F - You only buy this if you are a WHALE WITH TON OF GEMS!