Gilbert Arenas Unloads Calabasas Mansion and Can Now Afford Private S

The money Gods have answered Gilbert Arenas' prayers -- because just days after he claimed he couldn't afford private school for his kids ... the ex-NBA star made a cool $600k in a real estate deal.

TMZ Sports has learned ... Gilbert sold his Calabasas mansion for $3.35 mil -- which is GREAT, considering he bought the place in 2013 for $2.75.

Gilbert and Laura Govan initially lived in the home together -- but he gave her the boot after they split up in 2014. Gilbert claims he now lives in a nearby apartment.

Gilbert had plenty of memories in the home ... like the time he took a cinder block and smashed up his baby mama's Mercedes right in the driveway. Good times ...