As for buyers, it certainly helps.
We had a relative who died and on selling his house, we got an over-the-counter (pub counter) valuation from a local agent, which was 'wouldn't give you $100K for it in its current condition'.
The grounds were overgrown with weeds and other plants, you could put your hand in a kitchen cupboard and end up wrist-deep in cockroach mess, bathroom needed a good scrub, other cupboards were full of ltrs received several years ago (nothing was ever thrown out).
A few weekends with a chainsaw, mower, rubbish skip and the same agent bought it for $160K a month later.