I would suggest that he needs to get on PCOA and search for similar threads. I've not heard of the R51's having an overly expensive timing chain replacement - it's possible the dealer just didn't want the job, so quoted high. Being a dealership with pretty-much guaranteed work ahead of them, they have that luxury.
I've had the timing belt done on our R50 Pathy, and prices varied wildly. Local dealer wanted $1600, Ultratune, etc, could do for $1200. Our good independent mech did the job for $800 - which is only one of the reasons why we use him. Pays to shop around if you get a high quote.
Glad to hear he did it himself, unfortunate to hear it didn't resolve the issue.
Matto