Well I earn roughly that amount and I've bought a house. Not a £160,00 one mind, can't afford that!
As Hymie has said, you can usually borrow 4 or 4.5 x your salary so your friend is looking at a mortgage of roughly £80,000 - £90,000. He will also need a deposit of about 10% of purchase price so I would say that he should be looking at buying around the £100,00 mark maximum.
Don't forget that there are also givernment schemes to help first time buyers get on the ladder. Another thing to consider is his age, at 45 a 25yr mortgage will take him to 70 before its repaid and I wouldn't like to be repaying a mortgage at that age.