I was writing a poem -no profits anywhere in that ;)

My slang for $500 is....

a shitload of money!

this reminds me of Buck's Song in Heinlein's "Time Enough for Love" in which Our Hero (aka Heinlein) is a "professor" in a whorehouse and the song refers to a fin and a sawbuck. And an overcoat, but I couldn't find it online.

there's a pawn shop on the corner
where i usually keep my overcoat.
there's a trading post by the pawnshop
where my sister sells candy

http://www.scribd.com/doc/4801751/Time-Enough-for-Love

there's a hook shop above the pool hall
where my sister makes her living
she's a good sport i can spring her
for a fin or even a sawbuck
when not holding or the horses
have been running rather slowly

oh, good job!

I've heard it called a "half-k"