I can echo a large part of Brian’s post. It’s important to get a good handle on taxes and how they work – the percentages involved are much higher and you’ll need to build up a cushion of cash to cover VAT payments and your tax bill (which you won’t know until the last moment, a few weeks before you have to pay).
If you want a basic idea of how much you need to budget for, and how much will actually be left in your pocket, there’s a good guide here: http://www.tjtaylor.net/english/teaching-taxation
There are also some other FAQs we put together to help teachers new to Italy, for example on contracts, visas, and things to look out for.
Hope they help!