The costs for mechanical traps are completely bizarre. A 30 ft camouflaged pit trap costs 3,000 gp to buy. This becomes especially ridiculous when you look at the rules for making traps (and of course, in many cases traps need to be built on the spot - you can't exactly go out and buy a pit and put in your dungeon).
A camouflaged pit trap is a 30' deep hole with a well-made cover on it. The market cost is 3,000 gp, and since a decent craftsman does 40 gp's worth of work per week (skill +10, take 10, multiplied by DC 20, divided by 10 to go to gold from silver) building one takes 75 weeks - 1.5 years. Not to mention a materials cost of 1,000 gp.
