Find/Change Grep only finds one instance per paragraph, where am I going wrong?

Hi,

I've been using a Find/Change Grep to find any price with a comma and change that comma to a thin space (Newspaper's editorial style).

But the Grep only finds the first instance of this per paragraph.

Sample text...

"$200,000 $200,000 $200,000.

text at start of paragraph $200,000

$200,000 text at end of paragraph

tab     $200,000."

In the sample the grep would miss the second and third price on the first line.

I've been using...

Find...

(?<=\$)(\d{3})\,?(\d{3})

also tried (\$\d{3})\,?(\d{3})

Change to...

$1~<$2

Is there anything I can add to find these last two prices?

I've been using this in combination with Batch Find Replace script, so different greps are set up for 5,6 and 7 digit numbers that start with $.

Thanks.