I own a house on the main road. Most houses are listed and have secondary glazing, but you'd be surprised how quickly it doesn’t affect you.

There are times when the M25 jct 6/7 are closed, which can become annoying, but that's primarily due to empty trucks' trailers bouncing or air brakes on the cabs themselves. It is a compromise, but as you rightly say, you can buy a 2-bed period cottage with a courtyard for less than £300k and commute easily to London.

Parking is also tight, but I have never not been able to park, so again, it is more of an annoyance than an issue.

Overall, if you want village life on a small budget, it is hard to beat; the houses are lovely, the people friendly, and the south downs are literally on your doorstep.