Floyd Mayweather Jr. Is Warming Up to Retirement ... with $440k Shopping Spree

Floyd Mayweather Jr. is basically wearing your mortgage on his back while he roams around Europe, settling into life as a retiree.

We found out Floyd picked up this little number in Milan on Friday during a 400,000 euros shopping spree, because he obviously thinks it looks good ... but mostly because he can. We're told the coat ran him about 10,000 euro.

Floyd's easing into retirement like a college grad -- tramping around the Continent -- except if he stops at a youth hostel ... he's probably buying it.

Before Italy ... he hit up Russia, Turkey, and France. Thursday he was strolling around Monaco like a sharp-dressed man without a care in the world ... and several hundred million in the bank.