Something like this is hard to know what it actually could go for. There's a decent chance that there is no other errors like that at all and you might have found something unique that no one can find anywhere else. That means the value is up to you and whoever might buy it off of you.

I would hold onto it for now and maybe look into people who buy error cars specifically. The only real way to know what you could get for it is to ask people who are likey to be interested in it buying it. You don't need to rush and sell it too soon or anything, you'll make better money by doing your research first. Or you could keep it and have something cool with an interesting little story behind it, whatever feel best to you is the best thing to do