valve clearance

So I've got my 12K miles service coming up which involves the valves being checked and adjusted if required etc. I've been quoted £600-800 for the whole thing, is that about right? Seems a bit steep. Does it also have to be done at an Aprilia dealer? Thanks in advance.

Hi all, Has anyone here done their own valve clearance checking for the 12,500 mile service? Any tips or things to look out for? Also how easy is it to get hold of the right shims, if they needed replacing? Cheers