Tyvek One Pound Note to be Discontinued as Legal Tender

Isle of Man Today reports that (Tyvek) "Plastic pound notes to stop being legal tender" in England on October 31, 2013. From the article: "The Tyvek or ‘plastic’ £1 note, of which 305,000 remain outstanding, was first issued in November 1983. The Manx 10-shilling note was introduced in 1961 and the 50p note in 1969. It is believed that some 390,000 of these notes are outstanding."

However, some Tyvek 1 pound  Isle of Man banknotes are selling on eBay for much more than 1 pound!

According to Wikipedia, Costa Rica and Haiti have also issued Tyvek banknotes.

Tyvek is referred to as plastic here as it is made of high density polyethylene (HDPE) fibers.