My initial thought was: That is a lot of money for the work involved, it seems very excessive to me anyway.
Saying that, three tyres are £150- 180 right away...
The question is: Can you DIY or do you know anyone who is handy to help?
The brake cable boots are easy enough to do for any humble home mechanic as is the cleaning off, treating and re-coating the under seal.
The power steering pipe is a little more of a task but still very achievable at home and used but good replacements are available readily for a fraction of the cost from many of our reputable specialist breaker on this forum. As is the gear selector with full tutorials on here.
With sensible spending and the fact it isn't that difficult a job to complete the tasks, you can pretty much half that figure and they are going to get a good car to boot.
I certainly wouldn't scrap it.
Maybe all the family members and friends could all do this together as a project to help out.... There is bound to be someone handy with the spanners amongst them for beer tokens and it's a good cause too.
If they got stuck or simply needed a "how to" on advice, I'm sure we can help you and them out....
Or alternatively... Contact your local forum administrator and ask if it's possible to get a meet together of the local Alfa owners who many have years of experience as a charity bash and work on the car FOC...Since you are not repairing it to gain profit but to help someone out less fortunate..... Throw in a BBQ and beers as payment and everyone is then happy