Since the beginning of its career, Blind Guardian had always has collectors, for example the promotional EP of Follow The Blind, limited to 500 copies. This is a green two-tracks disc with Banish From Sanctuary and Hall Of The King. It can be found occasionally on eBay for around forty euros. Although it is not that expensive it is one of the most rare release of the band.
The first pressings of Battalions Of Fear, Follow The Blind and Tales From The Twilight World are also rare. They were released respectively in 1988, 1989 and 1990 on No Remorse Records, the original record company of the band who was bankrupted during the tour for Tales From The Twilight World. However they can be found on eBay for around twenty euros each (they are not worth more so do not buy them from a seller asking for a huge price).
Among some Japanese pressings man can find some CDs imitating LPs of Tales From The Twilight World and Somewhere Far Beyond. It can be discuss whether they are actually rare or not (like many CDs) as the number of CDs pressed is unknown. There is also a Japanese edition of Imaginations From The Other Side, still easy to find. The edition contains a 28 pages booklet (with many pictures) and a hard paper sheath with a different artwork. This album and the subsequent tour had a huge promotion compared to previous albums, so postal cards with pictures of shows were available. Promotional boxes were send as gifts to the press and members of the Blind Guardian staff.
Imaginations From The Other Side, Nightfall In Middle-Earth and the single And Then There Was Silence were released on picture LP, limited to a few thousands copies each. They are not so easy to find however they are affordable but Imaginations From The Other Side which is the most expensive of the three.
A Twist In The Myth was also released on a limited version with 1 000 copies. This edition was a box set in the shape of a book, with various goodies. This box was sold for excessive prices on auction websites, sometimes the triple of the original price.
During the year 2007, for the 20th anniversary of the band, Charlie Bauerfeind remastered the first six albums of Blind Guardian (from Battalions Of Fear to Nightfall In Middle-Earth), as well as the live album Tokyo Tales and the compilation The Forgotten Tales. Those new versions includes various bonuses (singles and demos, nothing previously unreleased). Booklets were completed with additionnal liner notes from the band members and new drawings. The cover arts were slightly improved, as well as the logo. Battalions Of Fear and Follow The Blind were completely remixed. Those CDs were sold separately in Europe but a boxset containing the 8th albums was released in Japan. The box had the cover art from Imaginations From The Other Side on its front. If you put the 8 CDs chronogically on your shelves, a modern version of the A Past And Future Secret cover appears (see the picture).
Among all that there is also different versions of albums and singles for different countries. For example there is 5 bonus tracks for A Night At The Opera: one for each of 5 countries. Consequently this is a puzzle for the people collecting who want to have all versions of each album. There is the financial aspect obviously but also the difficulty to find the correct version and to not buy bootlegs imitating official version sold by sellers with little morality.
I advise you to visit www.blind-collection.com to have more details about all the releases by Blind Guardian as well as other rare objects.