You can replace the entire motherboard for around the same price. We've seen a number of posts over the past 12 mths or so with this 'replace power IC' fix suggested, but nobody has posted after saying the repair was carried out successfully.
It involves replacing an individual component on the motherboard, these components are tiny, and Samsung service centres/almost all other repairers won't even attempt such a repair. If this repair is unsuccessful, you will end up having to pay for a motherboard replacement + the cost of the failed repair.
So if the plan is to keep the phone, insist on motherboard replacement. You can source a 2nd hand one online yourself & pay a mobile repair shop to do the replacement (and many mobile repair shops may even be able to source one for you), and as I said in my first para, this will cost you not a lot more than what you've been quoted for this dubious repair, but you will pretty much guarantee to fix the phone first time unless there's other components not working.
By all means choose the option you've been given (replacing the individual component), but be aware there's a fair chance it may not work, and if this is the case you'll end up with extra expense if you end up needing the motherboard replaced.
If it was me, I'd want it fixed right the first time.
Anyways, this is my last post to this thread. Nothing personal, but I've given you the options, up to you/your brother to decide what you want to do, no amount of further to-ing/fro-ing in this thread is going to change that.
If it's important enough to cause you grief if it's lost, back it up. No excuses
Trolling for thanks is lame
Does Samsung's auto-brightness implementation crap drive you to self-harm ? A solution !
Failure to search is the leading cause of male impotence on XDA
If you don't know how to recover if things go wrong, what are you doing flashing custom roms ?