One of the best things a game developer can do for their game is allow cash shop items without real cash to reward dedicated players who have played the game, which is an option Echo of Soul allows. I strongly believe in rewarding those dedicated to playing because even if they don't support the game directly, by playing they keep a healthy population in the game, which those who do support or are willing to support the game need in order to continue to want to play. 

Anyway, the system is rather simple. You obtain Magic Eggs then hand them over to the Magic Egg Merchant who then will grant you a reward. You only need a few of them to get something and you get some randomly through a variety of means. However, let's start off with the goodies that you can cash these eggs in for and where. 

Magic Egg Merchant 

The Magic Egg Merchant is in most "towns" that have a local economy. If there is a shopping district, then there is probably an egg merchant. The first town with one is Mnemos Town, but there are many other locations where you'll be able to cash in your eggs without having to use a teleport.  

Items Purchased with Magic Eggs 

You can buy the following items: 

Njord's Blessing 

A 2 hour buff that grants 4% attack damage. 

Cost: 23 Magic Eggs (19 AP) 

Edun's Blessing 

A 2 hour buff that grants 4% defense. 

Cost: 23 Magic Eggs (19 AP) 

Dungeon Ticket 

This item grants you increased access to dungeons. Grants you 2 additional tries at a solo dungeon and 1 additional try at a party dungeon (up to 20 / 10 extra tries). 

Cost: 57 Magic Eggs 

Magic Lamp 

Basically a lockbox, gives you a random chance at different items. Mounts, pets, costumes, bags, etc. all can be located within this magical wonder. 

Cost: 86 Magic Eggs (149 AP) 

Safeguard 

Protects item enchantment. Protects +7 jewels and below from being lost when you attempt to upgrade. 

Cost: 231 Magic Eggs (399 AP) 

As you can see the best bang for your buck is the Safeguard which saves you a lot of cash when you're doing enchantments, otherwise the Magic Lamp is a great way to get a lot of awesome cash shop items, without having to pay. You just have to let lady luck be on your side. 

Obtaining Magic Eggs 

You'll obtain magic eggs throughout your adventure. They come mostly from the daily quests at level 60 and your daily login reward, but they can also be handed out by GMs for various events (both in-game and on the Aeria forums) along with the level reward lockbox that progresses with you throughout the game. 

When I first started, I gathered up 40 of them rather quickly, so they're not super rare, but will require some work to obtain.