The cost for a single is 100 gems, while a multi is 1,000 gems. For every pull you do, you get mileage tickets, which can be used to exchange for the rate-up unit.
You can save these tickets as long as you want for moments when you have no resources to pull or you just want more copies of the character:
If you pull a character you already have maxed out, you get common shards you can use in this shop. You still get mileage even if the unit is 5-stars, this is a different currency.
You can use common shards to buy dupes for all the characters in the game, since there is no real limited units.
When it comes to Eldains, you can get some of them here with a limit of 10 shards and they are more expensive (40 certificates per shard vs 15 certificates for normal units).
Trickcal uses a card system which you can obtain in multiple places. These cards are used in combat and can be upgraded by collecting multiple copies of the same card:
Please make sure you always check the daily shop and buy all the cards available with gold. If they cost gems, it’s up to you if you want to use premium currency here or pull for more characters.
When you pull cards you don’t get mileage tickets, but instead a different currency similar to certificates but with no limit on how many shards you can buy.
You can also exchange this currency with normal mileage tickets 1:1, which is not recommended. It’s a waste considering how expensive that mileage shop is, so please just save it.
This shop is really expensive so please do not use this currency unless it’s a unit you really love.
Let me reiterate. You need 100+ shards to max out a character (stars and special item), and each shard costs 20. Don’t spend this currency unless it’s a character you love please.
Like most gachas, Trickcal also features a friendship banner where you can get units.
I can’t find any information that says the rates are different in-game, so I’m assuming it’s 3% for this banner too.
Make sure you add friends and not only give points daily, but “clean” their rooms for random free resources.