eBay glove seller "junkonsale" sold these rare LaCrasia long black leather opera gloves for $123.50. These gloves were a size 7.5 (M) and measured an impressive 26.75" long.
As a previous owner of LaCrasia gloves, I will vouch that they're not fancy (unlined and unhemmed), but the leather is very soft and the gloves are well-made to last a long time.