I would like to get a show jacket.. but I have a 23" waist.. and when I went to the tack store.. even a 6 didn't fit.. so unless yours is a super small fit.. It won't work for me . Other than that... find a horse classifieds forum for your area.
.. like my area has HCBC Forums • Index page .... if your state/province has a website like that .. that will be your best bet. Otherwise, Ebay and Craigslist are good ones.