That JQuery plugin may be a worth for IP2
Test the demo form and see how numbers are formatted as they are typed with the correct decimal symbol and thousand separator (point or comma), with currency symbols, percent symbol, and more.
Looks good but is is really necessary.
It is just as fast and correct doing it in PHP before rendering the page.
The times I would recommend this is when there is dynamic updates to figures on the page, for example a number that is changing all the time (like exchange rates), or an ajax table that is fetching data (for example previous page, next page) dynamically.