Kaley Cuoco -- Now That I Have Khloe Kardashian's Old House ... I'm Selling Mine!

Kaley Cuoco just picked up Khloe Kardashian's old house in Tarzana -- and it ain't gonna pay for itself -- so now the "Big Bang Theory" star is unloading her old one.

As TMZ first reported, Cuoco snatched up KK and Lamar Odom's old 7-bedroom 8,000 sq. ft. home for $5.49 million -- quite an upgrade from the Sherman Oaks spot Cuoco just listed.

Her old place is a piddly 5,233 sq. ft. ... with 5 bedrooms and 5 baths -- and her asking price $2.795 million... only slight bump from the $2.4 mil she paid for it.