Free: Contests & Raffles.
Never used one but would be courious to hear from someone who did. I have trapped many moles but have my doubts that this trap would work well. There is no way to tell where the tunnel is when you stick the trap in the ground. Also, tunnels can be really deep or shallow. I would think the success rate would be low with this trap. More of a luck type of thing but I could be wrong.
Albanos traps are the way to go. 50 moles and counting my pasture is pockmarked with them.
The absolute best traps are molepro.