I thought your comments were rude.
The answer, as always, is it depends.
We have been helping DD buy her first home, both with a deposit and, because she works long shifts, with looking. (The estate agent assured me I was not the first mum to do this.) She completed 4 days ago, so pretty recent.
She discussed finance with the mortgage advisor. It was a really fast moving market with many properties going for over asking.
As it turned out she paid exactly the theoretical figure discussed with the mortgage advisor, the mortgage valuation was exactly the amount she was paying (unusual), the survey did not throw up any unknowns (the roof will need work, and the kitchen extension is a bit dodgy, but almost all her neighbours seem to have done the first as part of replacing/extending the second. A project for when she is promoted and can afford to extend her mortgage.) She was also lucky that the vendor sold her white goods, curtains, beds, sofa and dining table for £2,000.
After costs she still has some savings (roughly 2.5% of the purchase price). It is unusual for everything to be on budget. She might have had to pay more for a property, the mortgage valuation might have been lower, the survey might have thrown up urgent works, she might have had to fork out immediately for white goods curtains and a bed. The flex would have come first from her savings, then by increasing the money borrowed (on less favourable terms) or by squeezing the reluctant bank of mum and dad. This did not happen in part because she had worked out in advance where she could afford to buy and because she lives in an area where property prices are relatively low. If she was in London it would be completely different. Just to get a first step on the ladder it would have to be a fixer upper, full use of savings, maximum mortgage, and old mum and dad would be looking at a summer staycation.