A, uh, personal eccentricity of mine is to treat dollars like any other unit written after the amount and optionally taking SI prefixes (At least in any writing I can get away with it). It's doubly nice because it plays well with rates/other composite units.
So:
$1,000 -> 1 k$
$1 million -> 1 M$
$1 billion -> 1 G$
$100,000 per year -> 100 k$/yr
I'm sure it'll never catch on broadly, but it's conceptually pleasing to me.
Technically, k, M, G, and the rest are SI prefixes created to be used within SI system of units. Those may be useful as finance prefixes too but it just happens that there already is another set in use.
So:
$1,000 -> 1 k$
$1 million -> 1 M$
$1 billion -> 1 G$
$100,000 per year -> 100 k$/yr
I'm sure it'll never catch on broadly, but it's conceptually pleasing to me.