Maybe bring it up casually in a conversation with your neighbor? Like, "what channels are you getting with that dish?". Chances are it's not being used anymore but it looks like it's in good condition
Can't hurt to ask. Look at it as an excuse to be neighborly.
I have been amazed though at times I have stopped by to ask about an obviously unused dish, and they seem to want to recoup the original cost of the receiver(s) cabling, and dish assembly. Then they make you feel like they have been insulted when offered $100 if it's in real good shape... You have to be prepared to walk away too.
I think Kraven means a video of you hitting your dish with a lawnmower