Craigslist maybe?
The dish won't be worth much as I can see that not only is it not SWM, it is at least a couple years old.
Also, keep in mind that the mast and arms will be missing the foot plates as they should be left where they are because they are keeping your roof sealed.
Not that it can't be resealed but if the installer used bishop tape like he should have, it will rip the shingle up with it if you attempt to remove them.
Considering that I can buy a complete set up brand new off ebay for $75 or get a free one by dumpster diving at my local Mastec office, used ones or really worthless.
But, you could try selling it on ebay, it might be worth a few bucks to somebody.
However, instead of worrying about selling it, how about just climb a ladder with a 1/2" wrench remove it yourself.
You won't even have to leave the ladder and you will save more money then you will ever make off the dish.