AIBU to think many Mumsnet posters seem to be high earners?

Exactly. I know a few people with millions in the bank, plenty of assets and and you would never ever think it 😆

I think you might be wrong about people with money, people with money do look like they have money, everything they wear says money but not in a wearing a CD t shirt kind of way.
The men are easier to describe they look like they quietly wear their handmade suits and shoes, their cashmere jumpers and their tailored shirts, they excel at the off duty preppy look, more often than not, look fit and healthy, they take care of themselves. They do look obvious - that's the point - it takes knowledge to dress in an understated way that screams money.

I think you might be wrong about people with money, people with money do look like they have money, everything they wear says money but not in a wearing a CD t shirt kind of way.
The men are easier to describe they look like they quietly wear their handmade suits and shoes, their cashmere jumpers and their tailored shirts, they excel at the off duty preppy look, more often than not, look fit and healthy, they take care of themselves. They do look obvious - that's the point - it takes knowledge to dress in an understated way that screams money.

I suppose we earn relatively well (six figures but not seven) but we don't have loads left at the end of the month. Our house necessitates a big mortgage, cleaner and gardener. We have to take all our trips away in the school holidays which means both beach holidays and winter skiing are more expensive. We have invested in electric cars and solar power to save on fuel costs but still need to run a back-up generator for some of the outbuildings (pool room, stabling etc).

Once we have put a good chunk into savings, longer-term investments and pensions, there is relatively little left over for our monthly clothes allowance, subscriptions, classes, days out, nights out, hair, make-up, treatment, kids stuff and treats. By the end of the month, we only have a small surplus.

I am not saying we are on the breadline, but we are hardly living private jet lifestyle!

I suppose we earn relatively well (six figures but not seven) but we don't have loads left at the end of the month. Our house necessitates a big mortgage, cleaner and gardener. We have to take all our trips away in the school holidays which means both beach holidays and winter skiing are more expensive. We have invested in electric cars and solar power to save on fuel costs but still need to run a back-up generator for some of the outbuildings (pool room, stabling etc).

Once we have put a good chunk into savings, longer-term investments and pensions, there is relatively little left over for our monthly clothes allowance, subscriptions, classes, days out, nights out, hair, make-up, treatment, kids stuff and treats. By the end of the month, we only have a small surplus.

I am not saying we are on the breadline, but we are hardly living private jet lifestyle!

I suppose we earn relatively well (six figures but not seven) but we don't have loads left at the end of the month. Our house necessitates a big mortgage, cleaner and gardener. We have to take all our trips away in the school holidays which means both beach holidays and winter skiing are more expensive. We have invested in electric cars and solar power to save on fuel costs but still need to run a back-up generator for some of the outbuildings (pool room, stabling etc).

Once we have put a good chunk into savings, longer-term investments and pensions, there is relatively little left over for our monthly clothes allowance, subscriptions, classes, days out, nights out, hair, make-up, treatment, kids stuff and treats. By the end of the month, we only have a small surplus.

I am not saying we are on the breadline, but we are hardly living private jet lifestyle!

I don’t know - DH and I are both high earners and buy clothes from normal high st shops (M&S, H&M) and have bought from supermarkets.
DC were/are also dressed in similar.
We are not scruffy though.

Same with cars - second hand non-luxury models.

I suppose we earn relatively well (six figures but not seven) but we don't have loads left at the end of the month. Our house necessitates a big mortgage, cleaner and gardener. We have to take all our trips away in the school holidays which means both beach holidays and winter skiing are more expensive. We have invested in electric cars and solar power to save on fuel costs but still need to run a back-up generator for some of the outbuildings (pool room, stabling etc).

Once we have put a good chunk into savings, longer-term investments and pensions, there is relatively little left over for our monthly clothes allowance, subscriptions, classes, days out, nights out, hair, make-up, treatment, kids stuff and treats. By the end of the month, we only have a small surplus.

I am not saying we are on the breadline, but we are hardly living private jet lifestyle!

I suppose it depends if like the OP suggests high earners are on £60k a year - I'd say I agree with you.
People with money I'd expect them to be on at least £300k each a year. Total net worth of somewhere between £5-10m. But I accept we all have different views on this.

We are much more towards your version than OP’s.