The 50-0 boxer -- one of the best ever to enter the ring -- wore the luxury fashion boots courtside while the Miami Heat took on the Phoenix Suns at FTX Arena on Wednesday.

The black and ivory footwear are Balmain waterproof apres-ski boots, made with Polyamide and calfskin.

Mayweather made sure he matched with an oversized Balmain cotton T-shirt featuring the fashion line's monogram print and name across the chest. The shirt costs $650 on the Balmain website.

So, the fit -- not including the diamond watch, bracelets, jeans and cap (which surely go for thousands of dollars) -- costs $1,445!!

Showing out at basketball games is Floyd's thing -- just a few weeks ago Mayweather sat courtside at the Spurs-Heat game, and the 45-year-old wore a ton of diamond chains around his neck.