They can range anywhere between $2.50 and $5 a piece, depending on if they are used or new. There are 11 chips needed. That's a (worst case) scenario of $55. Now factor in the cost of an original, factory MK3 security chip (really a rare item) plus the labor to do the burning/erasing, add in some profit, and you're near the $150 cost. Like Tony said, I'm using the "AnyU64" version of the roms with lets me get away with not needing an original MK3 security chip, which is roughly $40 cheaper by itself.