if you did $dollar='$'; this will work however this is a bad
idea. Have them do this:

Script:
$a=&random(1,10,.01);

Text:
You have $${a} monies.

If they want to use $ in the answer they will need to do a string
answer type. They will also need to do this:

Script:
$a=&random(1,10,.01);
$answer='$'.$a;

Text:
You have $${a} or $answer monies.

Response:
<stringresponse answer="$answer">

You can also use:

<display>&prettyprint($var,'$2f')</display>