Check out the US ebay . A lot will break up newish bikes down to nuts and bolts far more so than here .
Also there is a web site "boats .com " (something like that google search it) that has parts lists for a lot of bikes with an attached price list for what they have in stock .
They have a new barrel fo my 98 WR @ around $300 us and Yamaha aus has them for nearly $1200