That's money, But, when you take labor (a drill foreman isn't a cheap employee, at least 1 helper, normaly a locator, and a digger), equipment (2 trucks at $80k, drill at $250-400k, vac trailer, mud mixer, locator, sonde, pipe, pipe reel, any HDPE fusing equipment), insurance, possible (eventual...) damage claims; it's not as rosy as people think. It is, however Fast, and often cheaper than the alternative (open cutting a road; MOT, flowable fill, milling, and asphalt).
Replacement rods, heads, sondes, are $$$.
What's a full basket of 10 ft rods cost? I would guess $200/ea, x 38, $7600. And those are a wear item.