Power steering fluid leak from pipe split and power steering unit gasket (?). Quoted £1500 approx. to fix by Lexus seller - is there a cheaper alternative?

 

first off welcome. Genuine Lexus high pressure power steering hoses are very expensive brand new, up to $4-500 USD. These are known to leak over time in other 2JZ applications, and a used one would suffice, which could be had for less than < $100 USD. There are other hoses (see diagram), which definitely add up. Don't know what the 1500 pound price tag entails, but other high priced items would be the power steering pump and power steering rack.