Add accounting.js to your page. Refer to http://openexchangerates.github.io/accounting.js/ for more details on how to do it. If you are using JSFiddle though, you can just add it as an external resource to the left menu. You can add a link to CDN, which is serving it, for example, https://cdn.jsdelivr.net/accounting.js/0.3.2/accounting.js.
This filter will be extremely simple:
Vue.filter('currency', function (money) { return accounting.formatMoney(money) })
You can try it out with a one-liner in HTML:
I have {{5 | currency}} in my pocket
It will default to dollars, and it will print I have $5.00 in my pocket.
