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Reminds me of Rick Astley's "Never gonna give you up / never gonna let you down". But I guess you'd have remembered the original Rick Roll, wouldn't you?
Fuhrmann, es kostet dir noch dein LebenOh, and I think it had a piano in there. I think the piano went sort unison with the melody in the third line (the "blank blank blank blank" one). And the third word there is shorter than the others. Daah Daah Dah Daah. I can hear it in my head, but I fear my explanations are only making things more muddled.
A quick google ('song finding a buffalo nickel') tells me your Buffalo song is probably this one: https://www.youtube.com/watch?v=D17ItviO-nc
Oh my god, I found it. I only had some of the words right, but I finally googled just the right ones. Turns out it was Adam Lambert's "Whataya Want From Me" https://www.youtube.com/watch?v=X1Fqn9du7xo
Whew. My brain hurts a little.

I've got two, though one is pretty much a lost cause.
1. This played on a country station, maybe 10 years ago. It was sung by a male, and it was about finding a buffalo nickel, and realizing it only had three legs. I think I only heard it once, and I've been trying to figure out what it was since then, so I don't have much hope.
2. This, I have no idea how old it is, and can't even remember if it was sung by a man or a woman. The lyrics that I can remember (probably incorrectly) are: "I won't give up blank blank blank blank blank blank blank blank blank I let you down" This is the chorus, I'm fairly certain. For the life of me, I can't remember the lines in the middle. I was reminded of this by Red's Feed the Machine. The line "We fall in line" has a similar tune to "I won't give up" (or whatever that first line is).