A quick google suggests that in 1986 the average London house was £55k. As a tangentially relevant point of comparison to that, in 1978 my parents house in west of Scotland was £9k.

Regarding Vernon...it wouldn't shock me if he was a couple of years older than Petunia. If she was looking to get a leg up the social ladder, finding herself an established businessman in London was probably her plan, it just went better than she actually intended when he turned out to be from the public school/country life background.

If he was something like 26 or 27 when they met, and she was 21 or so, then by the time of the prologue he's be in his early 30s. That works for him having nominally served his time as a salesman (likely mostly on the golf course with the senior management), and been rapidly jumped up to Director at his Dad's mate's company around the time he hit 30.

And its worth remembering that, even if he wasn't actually a phenomenally talented salesman, in the 70s and 80s there was absolutely a type of customer who'd choose who to buy from because they were "the right sort" - right background, right schooling, knows the right people, comfortable in the right sort of places, etc. He'd probably have been pretty decent at those sorts of sales.

 

Everyone knows the Dursleys don't have a dining room.

 

What? Its in the books that they do...

 

I was about to suggest Petunia moved to London in her early twenties, maybe even worked as a secretary at Grunnings where she met Vernon, when I thought to check. And, yep, that's canonically exactly what happened.

https://www.wizardingworld.com/writing-by-jk-rowling/vernon-and-petunia-dursley

 

A tale as old as time...

 

So do you think the Dursley's sex life is super vanilla or super kinky?

 

Barely extant by the time of the books I would think.

 

Normal on the streets, freak in the sheets clearly

 

Considering the state Vernons in even by the first book it's to be expected. The man's risking a coronary from even mild foreplay.

 

I always figured there could be another reason why Petunia goes around scrubbing the kitchen clean mornings and evenings. Whatever they do as a couple, I think it's kitchen-based. Also, I think there's mention of them being upset with Harry for sneaking into the kitchen at night to get a snack, clearly the reason isn't that they want him to starve, it's that they're worried he'll barge in on them when they have their pink bits out.

 

Did they have to order an extra strength kitchen table?

What a horrid mental image you paint.

 

You're welcome

 

It's probably reinforced and screwed deep into the floor.

 

That's Petunia you're thinking of.

My mental layout is more close to Ark's map than Taure's; although a few changes - staircase on the right of the hall, not the left (mine, and my childhood friends' were all on the right from the front door), and with the bedroom layout being Harry/Bathroom/Guest at the back, then Dudley and Master Suite at the front - I'd tend to think the child's room not share a wall with the master. So Dudley's being over the garage, with Harry's over the boiler.