Kim and Kanye Buy $20 MILLION Estate ... with Vineyards!

Kim Kardashian and Kanye West are buying a baller estate for mega-millions ... TMZ has learned.

Real estate sources tell us ... Kim and Kanye are in escrow for a 3 1/2 acre estate in Hidden Hills ... 5 minutes from Kris Jenner's house in Calabasas where they're currently living.

We're told K & K paid $20 million ... the house was listed for $21 mil.

It has 2 pools (one with a slide for North), 2 vineyards and a 1,050 square foot entertainment pavilion. Real estate people in the area call it "the jewel of Hidden Hills."

We're told Kim has been eyeing the home for months, telling people it's her dream home. And get this ... Kim and Kanye have been going back and forth to check out the house ... on Vespas from Kris' house to keep a low profile.

We're told escrow is set to close at the end of the month.

The estate was once owned by Lisa Marie Presley.