I've looked and looked and can't find another original, vintage 1980s pink triangle button out there anywhere for sale (just contemporary versions, and a few originals housed in archival collections). This one was produced by the Oscar Wilde Memorial Bookshop, NYC, which opened in 1967 in a small storefront on Mercer Street, then moved in 1973 to 15 Christopher Street. I found this one along with two other buttons from the era, which I'm listing separately--one by Keith Haring, the other from the 1983 Christopher Street Liberation Day, the predecessor to the Gay Pride Parade. I haven't been able to date this one exactly, but I think likely early 1980s. 

The use of the pink triangle by gay liberation activists dates to the early 1970s, invoked to raise awareness of its use in Nazi Germany. (In 1975, Dr. Frank N. Furter wears a pink triangle badge in "The Rocky Horror Picture Show") In 1987, ACT UP (AIDS Coalition to Unleash Power) combined the pink triangle with Silence=Death to draw attention to the the disproportionate impact of AIDS on gay and bisexual men, and the role of homophobia in slowing progress on medical research.

1 1/4" in diameter and in good vintage condition, with some surface rusting to the back.