Yeah, so 20% over + 10% deposit would mean needing £75k in cash savings
Again, a fuckload of money for someone on their own. For a couple each earning £28k, that's say 25% of their income saved over 5 years, which is entirely doable if you have shared living costs.
So, again, it's a lot of money - but definitely achievable for a couple in a way it isn't for someone on their own.