I have found some great prices around Mendocino (airbnb), however I am concerned about the drive. And it is beautiful there. Any other area a little closer to Sonoma where we would find the same beauty, beaches and prices?

Mendocino has its own special beauty. It's got the rugged coastline but also lovely coves. There is a pleasant walking beach where the river meets the ocean.
And you have first trails for hiking.

Beach areas south of Mendocino have a totally different vibe. You could stay inland along the Russian River (Occidental, Guerneville) and have an easy drive to either the coastal beaches or Healdsburg Wine Country area.

Occidental is a nice little hippie-vibe town, but it's not on the Russian River (near, but not close to "on").