Summer Olympic Games in Rome in 2024!
To quote Sir Alf Ramsey: "If selected.
It isn't a bad thing if you get it though, speaking from personal experience the feel-good factor alone is 'worth it', if you can throw in a reasonably sustainable legacy programme (more London (ignoring the West Ham situation) than Athens) even better.
There are plenty of other things to worry about when it comes to public finances, I worked in a council for a couple of months and saw (among other things) renovation staff spending a morning taking away large office dividers (which were in places they weren't really needed anyway), and replacing them with brand new ones a quarter of the size, and heard one of them say something about meeting quotas. Getting rid of small things like that (and the wages of middle-managers paid to focus on these things) and you have plenty of budget to get your country something nice.