There isn't a lot to be found out about the origin of this word.
However, I think I may have the answer for you.
I started my search by using google, and typing "a buck two eighty" origon
Now, I know I spelled origin wrong, however.... I didn't notice at the time...
So, when you go there, it askes you Did you mean a "buck two eighty" oregon?
I sais yes, for the heck of it and clicked the link...
It led me to
Which lists the term as ancestral, but not the origin.
So, back to square 1.
I went back to google and typed in "a buck two eighty" origin
And came across this link...
Which states... "I am reminded that there is a usage here in Wisconsin
-- I've been told it's local to the Manitowoc-Two Rivers area -- "a
It also says "I first heard this in New Hampshire. It was meant to be
a slur on the French on the Northern border. Said in a French accent,
"I'm goin down to ze fak toor ee to work for a buck sree eighty an
So, based of what I have read, it looks to be of American origin. One
of those lovley little sayings a witty person made up.
Hope that takes care of it for you...