k/M/G suffixes do not show when using a format string

See the jsfiddle below. Ideally I would like to see the numbers on the yAxis show as $20k, $15k, etc.

JSFiddle: http://jsfiddle.net/LdHaa/2/

I'd suggest making a format-able value to allow the formatting to happen at the formatSingle function level.  Here's a suggested approach, but it looks pretty ugly to me. (I'll leave it up to you guys to take or leave it)

You would be able to use the format string: "${value:.0Mf}"