diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..11f8b02
Binary files /dev/null and b/.DS_Store differ
diff --git a/storage/model/hamster.go b/storage/model/hamster.go
index d8a7ff3..8e63cb1 100644
--- a/storage/model/hamster.go
+++ b/storage/model/hamster.go
@@ -3,9 +3,10 @@ package model
 import (
 	"errors"
 	"fmt"
-	uuid "github.com/satori/go.uuid"
 	"hamster-tycoon/randomizer"
 	"time"
+
+	uuid "github.com/satori/go.uuid"
 )
 
 const (
@@ -58,6 +59,71 @@ func (h *Hamster) Die() {
 	h.Alive = false
 }
 
+func (h *Hamster) DeterminatePrice() int {
+	if h.Age >= 600 {
+		return 0
+	}
+	var price = 50
+	if h.Age >= 60 && h.Age <= 300 {
+		var diffAge, quotient int
+		diffAge = 300 - h.Age
+		quotient = diffAge / 25
+		price += quotient * 5
+	}
+	if h.Sexe == FEMALE {
+		price += 20
+	} else {
+		price -= 20
+	}
+
+	if h.Gestation {
+		if h.Age >= 500 {
+			price += 5
+		} else {
+			price += 20
+		}
+	}
+
+	if h.Age > 300 {
+		var diffAge, quotient int
+		diffAge = h.Age - 300
+		quotient = diffAge / 100
+		price += quotient * 10
+	}
+
+	switch h.ThirstLevel {
+	case Empty:
+		price -= 20
+	case AlmostEmpty:
+		price -= 10
+	case AlmostFull:
+		price += 10
+	case Full:
+		price += 20
+	}
+
+	switch h.HungerLevel {
+	case Empty:
+		price -= 20
+	case AlmostEmpty:
+		price -= 10
+	case AlmostFull:
+		price += 10
+	case Full:
+		price += 20
+	}
+	switch {
+	case h.GestationCooldown > 0 && h.GestationCooldown <= 7:
+		price -= 10
+	case h.GestationCooldown >= 8 && h.GestationCooldown <= 14:
+		price -= 5
+	case h.GestationCooldown > 15:
+		price -= 2
+	}
+	return price
+
+}
+
 func (h *Hamster) Grow() {
 	if h.Age >= MaxAge {
 		if randNumber(h.Age-MaxAge, 365) > 364 {