Shaq ain't down to outspend Jeff Bezos for the Phoenix Suns ... but if the billionaire wants to join forces in an effort to own the NBA franchise -- The Big Diesel tells TMZ Sports he's in for that!
Shaq says he initially had interest in buying Robert Sarver's share of the org. after the disgraced owner announced last month he was putting it up for sale -- but when he found out Bezos potentially wanted in, he was all out.
Shaq explained even with his deep pockets -- he's reportedly got a net worth of around $400 MILLION -- he wanted no part in competing with Bezos' checkbook.