I had a hard time spending 2500 for one of those things too so I rolled the cutting torch out of the shop.  Light the torch and set it like you were going to cut metal, then snuff out the flame.  Put the torch in the hole and count to ten or so, remove torch, light torch, then run the flame over the hole.   BAM!!!!!!  For best results do it right after it rains, ground is saturated and won't absorb the acetelyne.  You'd be surprised how far a mole run will go.

Like said above, wear eye and ear protection.