I was at a 5 day Festival/concert here in Switzerland earlier this year and Robert Plant played a few Led Zep songs and few newies... gotta say i was pretty chuffed to have had the opportunity to see the old guy!
Drugs have clearly had there effect on him as has time... so he is a little slow on stage.... BUT
on what i have seen with him and his band i'd spend 10g for you and your boy to have a once in a lifetime experience that none of his mate or yours will ever be able to say "yeah know what that was like"... Go for it... Go and party out with your boy and his mate...
rock on!

what better father son experience would/could one ask for?
you ver lucky man Mr Davmen