add buy/sell price attributes to item resources

Items/Weapons/Bow.tres

@@ -12,3 +12,5 @@ script = ExtResource("2_hjbs0")
 Instance = SubResource("Resource_mjj1w")
 Name = "Bow"
 Description = "A bow and arrow."
+BuyPrice = 0
+SellPrice = 0

Items/Weapons/DocLance.tres

@@ -12,3 +12,5 @@ script = ExtResource("1_fhdpj")
 Instance = SubResource("Resource_clkv8")
 Name = "Shungite Spear"
 Description = "It's a billion year old lance, spear that protects against unwanted invaders."
+BuyPrice = 0
+SellPrice = 0

Items/Weapons/Pugio.tres

@@ -12,3 +12,5 @@ script = ExtResource("2_j4tmu")
 Instance = SubResource("Resource_abrg1")
 Name = "Pugio"
 Description = "A sidearm dagger."
+BuyPrice = 0
+SellPrice = 0

Items/Weapons/Sword.tres

@@ -14,3 +14,5 @@ Instance = SubResource("Resource_qqiwa")
 Icon = ExtResource("1_j0i86")
 Name = "The Fool's Sword"
 Description = ""
+BuyPrice = 0
+SellPrice = 0