Question for Artists regarding prices

Hello,

I know each artist would put quiet a range to their prices for various works but I was just thinking this morning how awesome it would be to have a mural done on our front fence.

I have no idea what such a thing would cost though, like not even a general ballpark number. $2k?$20k? More?

Just looking to see what sort of number people throw out so I can either pursue it further or just forget about it right off the bat. Also don't want to insult someone when I approach them and be like "So $50 ya?"

Not sure if there's a generalized $lsw ft type thing people have but it's a 8' tall black corrugated fence, about 120' long split by a driveway in the middle. I assume prices would vary on the design so let's say maybe just a forest scene or something,like you would see on electrical boxes in the city to hide them.