How do you add custom prefix to Bricks select > options?

Hi guys, I’m sure this must be simple but I can’t see how/where you add custom prefix data, say a £ or $ sign to Bricks Filters that are using numeric CF data?

The obvious example is what I do not want is… a Bricks Select list containing…

250
350
410

Instead what I do want in the Select list is…

$250
$350
$410

The custom field data is created using custom Meta Box fields added by JetEngine in this instance, in case it makes a difference.

Many thanks guys - although I do want to add via Bricks configuration fields and not via custom functions etc, if anyone can shout that out.

Many thanks,

Q.