As stated in the thread linked to above, these are not technically "coins', as they are not legal tender; the "Order" that struck them is not the real Sovereign Military Order of Malta.
That being said, it is a solid gold 1 ounce object, and is therefore worth at least the bullion price (currently AU$1735). Unfortunately, this coin is not yet listed in the catalogues. The only "5000 liras coins" listed in the catalogue are
these from 2004 and 2005, though their weight/fineness must presumably be lower as the CV stated there is only half the price of a 1 ounce gold coin.
Unless, of course, the mint is being deceptive or evasive, and "99,9" gold content really means .0999 fine, in which case the gold content would only be worth AU$173.50. I'm afraid I don't know enough about these coins, or this mint, to know if this is likely.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis