Re-mortgage your house i'd say. Nissan parts are ridiculous price wise!! 3 years ago i had an old k11, only paid 250e for it but the wiper spindles were worn, they cost me 170euros for the 2 !!! i had to inquire did they get them mixed up with something else. Headgaskets are 90euro here so i can only imagine the fright you will get at the cost of a chain kit, i would guess at around £250-£300+ vat. Blue Point do a reasonably priced kit and i have fitted a few with no issues at all, i think the kit works out around £120-£140 stg