This is a whole other topic unto itself. Plenty of kits have giant rocks, or designed ground, etc that jack up the price or could have definitely been used for other options. The example I'll use is the beast skewer kill bow. A huge chunk of the sprue is a piece of land. This could have definitely been a plethora of other options as not to have exact copies of kits if running multiples. Hell, it could even been a second weapon type like a giant net launcher or something but nope, ground.