needs a clutch? is it good enough to ride it too see how everything is or needs clutch as in clutch is F'ed up or what where its not ridable. need more info than that is it running .. if its running talk him down telling him what it would cost to have a new clutch installed or fixed at some shop. so what i would do is this $1700 minus the cost of clutch new, minus any other broken missing parts, minus another $50 to $500(maybe more) . remember and maybe remind him , selling bikes in winter time they go for alot less, and double check the title to be free and clear, , find anything and everything you can to knock the price down or have them fix it first, if your not tech savy take it to a reputable bike shop to have everything checked out for a prebuy inspection. get there check list of whats good, whats is SUGGESTED and whats REQUIRED , for your list to show him to bring the price down ,& to help you decided if you want to buy the bike, if he does not let take it to a shop (with or Without you) then be VERY WARY of it , it may have problems he dont want you to know about, dont leave him alone with the techs or take to a shop of techs he knows as he may pay them off or something.
my Two pennies worth. good luck.
will this be your first buell?