Within a few weeks it arrived and Bingo! The true first appearance of a rare classic- in its entirety. Since then I've managed to get two more for a relative pittance- but now the secret is out. Good luck!
The first British book edition (published shortly after the magazine) is legendarily rare since it was recalled due to the misattribution to Byron. Later contemporary issues sell on the web for about $2000. So how much is the magazine really worth? I traded one for $6000 worth of magazines to a very astute collector friend of mine.
By the way, this story is the product of the most productive horror story competition in history. On a rainy summer night in Switzerland in 1816, a small group of people were sitting around and decided that they would attempt to write a supernatural story, among them Byron, Polidori and Mary Shelley(then Godwin). Polidori's Vampyre was not the first vampire story, but it is considered the basis for many other offshoots including Bram Stoker's Dracula (never appearing in a contemporary magazine). The world has continued its fascination with the blood sucking night creatures to this day, viv a vis "True Blood" on HBO.
Of course, Ms Shelley came up with a pretty good character of her own that night- Frankenstein: or the Modern Prometheus. see an excellent treatment at http://en.wikipedia.org/wiki/Frankenstein The first American edition did not appear until 1833 but it was extensively reviewed and excerpted in Portfolio in 1818.
The first American magazine printing of Vampyre was in 1819 in volume two of the very rare Robinson's Magazine, published in Baltimore (I own volume one but have never seen volume two).
For a great read on the subject, you can buy (or download to your Kindle) a great book by Tom and Dorothy Hoobler http://www.amazon.com/Monsters-Mary-Shelley-Curse-Frankenstein/dp/B000SESF46/ref=sr_1_2?ie=UTF8&qid=1249678527&sr=8-2 Sadly, this story helped to precipitate a falling out between Byron and his doctor and the despondent Polidori committed suicide (ingesting a cyanide compound, prussic acid) in 1821 at the age of 25.