I am more-or-less expert in vexillology (the study of flags). My expertise is particularly strong in North America at the level of city and county, but if I don`t know the answer I know a dozen people who do. So if there`s a flag in the newspaper or on TV that you have trouble identifying, let me know. I`ll do my best. But PLEASE DO NOT ASK ME TO APPRAISE A FLAG'S VALUE: (1) I have no expertise in that area and (2) even if I did, I cannot appraise something I can't see. Take it to a museum which has a specialist in textiles and the like.
In this field, I designed the flag of Carroll County, Illinois, in 1974 (see http://www.internetni.com/~lanarklib/index.html). You can see my personal flag at http://www.nava.org/memflags.htm