What a rip off!
We recently got a 50cm deep trench dug (for power) for $330 by a ditch witch type machine. The trench was about 100m long!
But in regards to telstra to get the phone connected we had to get a trench dug for the last 17m that hadn't been done, so that the cable could go to the telstra box in the ground. I opted to do it myself (ah yes it was hard work!), I just made sure to find out from Telstra (or their trenching contractor) what depth it needed to be which turned out to be 30cm at least,
So yes - saved myself a few hundred bucksI guess. I actually dug it to the concrete / plastic box, but it was slightly in the wrong spot - was meant to go to a plastic pipe sticking out near the box. Luckily the telstra guy dug the short diversion. Just as well because they didn't turn up on about 3 occasions to do the install & I had been waiting weeks! Would have been really peeved off it it was delayed again (having only a mobile with only just adequate reception is no fun).
But to answer the other question someone had, no we didn't have to pay for inspection and yes we had to pay the $300 connection fee!