Vue filter to ensure USD formatting prepended with a $. Could be even more terse by refactoring decimalPrice and returning one line, but more legible?
import Vue from 'vue';
Vue.filter( 'currency', value => {
if ( ! value ) { return '' }
const decimalPrice = Number( value ).toFixed( 2 );
return decimalPrice.toString().padStart( ( decimalPrice.length + 1 ), '$' );
});