The people who've got 4 or 5 ovens, and want to know how best to invest £75K they have spare, and who claim to make savings of £3K a month, make me laugh. In real life, these people don't exist.
I don't even know why they think this even sounds possible. If you actually had that amount of money to invest, why wouldn't you speak to a financial advisor in person, or at least post on a financial forum. Why mumsnet? 
I take it with a pinch of salt. I'm sure some are telling the truth, but some claim that they earn 150k, only ever work 9-5, have an easy commute, 3 exceptionally well behaved and intelligent children, loads of savings, holidays all the time etc. It never quite adds up.