There are 2 types of capsules, the common capsule (Green) and the advance capsules (Blue).

Green Capsules

To open the green capsule you need to use gold, the basic one is opening a single capsule which in most cases isn't worth it. You can also do the 10x pull, it's cheaper and you have get 1 blue capsule item.

Costs of opening green capsules

1x = 10k

10x = 90k

What can you expect to get?

Friendship improving items, experience shards, evolution cards, basic eso's, attribute training stones, gold bags, friendship breakthrough items

Blue Capsules

To open the blue capsules you need to use diamonds, the basic one is opening a single capsule, similarly to green capsules this generally isn't worth it, and the better option is doing the 10x pull which will not only save you diamonds but it will almost always give you better rewards as well as returns from events (providing there are events going on)

Costs of opening blue capsules

1x = 280

10x = 2488

What can you expect to get?


Important to note with the blue capsules is, everytime you spend X amount of diamonds in the capsules you have a 100% chance of securing a legendary pokemon, but these are random personalities so most likely won't be ideal for mid/late game.

The only time i suggest you do the 10x blue capsule pulls is when they have an event which gives you shards or something useful for doing the pulls, so you will most likely need to save 24k-40k diamonds before considering to do pulls.