There are 5 different categories of items at the shop:
Featured- Items that are bought a lot by players.
Monsters- Most monster eggs can be bought here. Note that better monsters cost more gold, crystals or friend stones to buy.
Habitats- Most habitats can be found here. Habitats are the areas your monsters live in. Each habitat has a different element specializing in that type of monster. If you place, let's say, a Whipster, (a fire-type monster) on a fire habitat, when you give it needs, it will earn bonus XP. Some habitats also take away some recovery time.
Boosters- Most boosters can be found here. Boosters are special buildings that specialize in a need. If you place a target (training booster) down, all monsters will gain bonus XP when their training need is taken care of.
Attractions- Most attractions can be found here. Attractions are building that generate gold after a certain amount of time.
The Currency Shop is where you buy currency with real money. The following packs can be bought:
Normal Gold Pack- 2,640 gold- $1.99
Big Gold Pack- 7,920 gold- $4.99
Huge Gold Pack- 18,480 gold- $9.99
Enormous Gold Pack- 42,240 gold- $19.99
Monstrous Gold Pack- 118,800 gold- $49.99
Ultimate Gold Pack- 265,320 gold- $99.99
Pile of Crystals- 40 crystals- $1.99
Sack of Crystals- 120 crystals- $4.99
Bucket of Crystals-280 crystals- $9.99
Chest Full of Crystals- 650 crystals- $19.99
Wagon Full of Crystals- 1,800 crystals- $49.99
Avalanche of Crystals- 4,000 crystals- $99.99
F-Stones (Friend Stones)
Pile of F-Stones- 200 F-Stones- $1.99
Sack of F-Stones- 600 F-Stones - $4.99
Bucket of F-Stones- 1,680 F-Stones- $9.99
Chest Full of F-Stones- 3,800 F-Stones- $19.99
Wagon Full of F-Stones- 10,800 F-Stones- $49.99
Avalanche of F-Stones- 24,000 F-Stones- $99.99