If there is no Line of Sight from the house then a pole-mount is free of charge from the Home Service Provider usually. If the installer CAN get a line of sight from some point on your house but you still prefer it on a pole there may be labor charges for the pole-mount as it is not considered a standard installation. The amount of the charge is usually set by the HSP but whether to charge it or not is usually at the sole discretion of the installer. For the Ka/Ku Slimline a 2" aluminum pipe-pole is normally used. Sunk into the ground between 30" and 36" and concrete around it. The installer should do a thorough site evaluation with you at the time of the installation to determine the options and what would work best for your situation.
For me personally, I hate trenching cable. It's time consuming, I just don't like doing it. When I run into a situation where a customer may want a pole-mount, I inform them of the charges they may incur, then say something like "However, if you would be willing to bury the cable on your own, I won't charge you"
Saves me a lot of time when doing pole-mounts LOL though I did run into one last week where the guy wanted his dish 200 ft down hill his backyard slope, behind a little storage shed, simply for the fact he didn't want to see the dish in any shape fashion or form from his house. Though I wasn't exactly looking forward to it, I was professional and didn't grumble, he even helped me do it and I knocked his fee down to 1/2 ^^