Ben Affleck, J Lo Get Real Estate Tips from 'Million Dollar Listing' Stars

Ben Affleck and Jennifer Lopez are on the verge of making a HUGE purchase together ... but before they do, "Million Dollar Listing: L.A." stars have a few things they should hear.

We got a clean-shaven Josh Altman leaving Craig's Tuesday night and wanted to know what's the best purchasing route for a couple that's not married. Altman, without any hesitation, says they ought to split the purchase down the middle.

Why? Altman says it keeps the transaction clean. But, what if Bennifer split up? He's got them covered on that end too. BTW, Altman says he's seen the Beverly Hills estate Ben and J Lo toured Tuesday ... and he's blown away by the compound.

We also got Altman's's sometimes BFF/sometimes nemesis Josh Flagg leaving Craig's and he offered a twist on how Ben and J Lo should buy the house. Hint: Flagg suggests a method available to all normies, albeit with a much higher down payment.

As we reported ... the Beverly Hills estate Ben and Jen toured has a main house that's 38,000 square feet. It features 12 bedrooms and a whopping 24 bathrooms. There's also a "guest penthouse" and a caretaker's house. #Insane.

Ben and J Lo also looked at the former Bob Hope estate in Toluca Lake. It's currently owned by billionaire Ron Burkle, and that's listed for a mere $40 mil.