Unlike the Garnet shop these rings are far more expensive! If you are a spender, of course pick these up and you will be able to craft your legendary rings for each set. 

Exp potions are always a necessity regardless of spending level. Yes you can survive without them but in order to really feel like you are progressing well and at a consistent rate it's nice to at least have the weekly potion to cover you for an extended duration. 

These mounts located in the Diamond shop are going to be quite expensive but with the price comes some really nice benefits to help you with your Potion amplification as well as being able to give you a lot of damage reduction 

From the early game and even into late game these materials have the chance of dropping from various bosses but if you want to rush your progression or don't have the patience to wait for one of these to drop or show up in the auction houses you can pick them up here to save some time but not save any money.