You can't, because land within commuting distance of a major city is going to have more people that want it, and be more expensive. You need to go farther out. I'm not super familiar with the Washington coast, but in Oregon places like Lincoln City, Yachats, Coos Bay, Otis, etc.

You can’t. (I just bought 12 acres 50mins within Seattle.)

Wow. Might I ask where? I'm thinking of places like the outskirts of Monroe, North Bend. I've heard of people doing this farther out on the Peninsula in places like Port Angeles.

You're about 15 years too late to find 'deals' in Monroe/North Bend area. It's seeing huge growth and property values are way up. There's not as much land as you think too since a lot of it butts up against state and national forests.

Well. Anywhere else? Should I go out to Wenatchee?

there's a lot of land on the WA/OR coast, but you won't find it cheap in a Seattle suburb, which is where a 30 minute drive along the coastline will take you

Expand to 1.5 hours or so drive and I bet you could find some options.