...what's available at the $300k price point are cookie cutter 1970s/1980s houses in subdivisions. Living in a subdivision like that would depress the hell out of me.

What specifically about this situation would depress you?

If you can identify that, how can you avoid whatever-it-is and still stay within a more comfortable range?

Also, if the neighborhoods are 20+ years old, I have to assume that there is at least some differentiation between houses and neighborhoods at this point.

My husband is the same way. It's the neighborhood format, I think. I don't know how to explain it. He has no problem living in town closer to neighbors, or living on a farm with lots of space. I'm not him, but if I had to convey the feeling secondhand:

There is something about subdivisions that recalls the lemming like path that people are told they should take and they end up in these cookie cutter homes- aka little boxes, like the 60s era song by Malvina Reynolds:

Little boxes on the hillside,

Little boxes made of ticky tacky,

Little boxes on the hillside,

Little boxes all the same.

There's a green one and a pink one

And a blue one and a yellow one,

And they're all made out of ticky tacky

And they all look just the same.

And the people in the houses

All went to the university,

Where they were put in boxes

And they came out all the same,

And there's doctors and lawyers,

And business executives,

And they're all made out of ticky tacky

And they all look just the same.

And they all play on the golf course

And drink their martinis dry,

And they all have pretty children

And the children go to school,

And the children go to summer camp

And then to the university,

Where they are put in boxes

And they come out all the same.

And the boys go into business

And marry and raise a family

In boxes made of ticky tacky

And they all look just the same.

There's a green one and a pink one

And a blue one and a yellow one,

And they're all made out of ticky tacky

And they all look just the same.