Floyd Mayweather Cops $250k Neck Bling

Floyd Mayweather is still finding ways to show us he's rich as hell ... this time it's hooking up with one of NYC's best jewelers and copping a neck piece worth A QUARTER MILLION DOLLARS.

The money man stopped into the Mr. Flawless jewelry store in Manhattan on Thursday and went HAM ... copping a "double lion head cuban bust down no lock."

We don't really know what the hell that means ... but we do know the gold and diamond chain weighs a monstrous 1,200 grams and set Mr. Mayweather back an INSANE $250k.

Floyd's been on a spree recently ... earlier this week we saw him cop $500k for his girlfriend Bad Medina ... the 4th car he's bought her in two years.