Every year since 1992, Montblanc has been creating pens that celebrate famous writers. In 1993, the pens in the Writers Edition were created in honour of Agatha Christie and based on the classic style of the early 1920s. According to Montblanc "around the cap, made of black precious resin, winds a snake made of 925 sterling silver, which hints at the creeping tension of the author’s novels and also serves as the clip of the pen. The eyes of the snake are set with two rubies that glint bewitchingly. The head of the snake is also engraved on the rhodium-plated 18-karat gold nib. Each Agatha Christie Writers Edition pen is also decorated with the signature of the grande dame of the crime novel."
Fountain Pens: Two types of fountain pen were made. The standard was in an planned production run of 30,000 units, though there is some speculation that MontBlanc did not use the full capacity and likely ended up with closer to 23,000 made. The original price was $595 USD. The limited edition pen with 'vermeil' (gold plated silver) for the embellishments was a much smaller run of 4,810. Both pens were available in medium or fine nibs. For the pen to be in original state the M or F sticker would still be on the barrel of the pen. Both pens would have a unique serial number engraved onto it citing its production number, i.e. xxxx/4810 (limited) or xxxx/30000 (standard). Some value a low number as more appealing.
Ball Point Pens: Only one type of ball point was made in a production run of 25,000 units, though again there is speculation that no more than 20,000 units were made. The original price was $350 USD. All pens will have their production number engraved on the barrel.
Mechanical Pencils: Only one type of pencil was produced in a 0.7mm size and with a total production run of 7,000. In the original state the 0.7mm sticker would be on the barrel.
Box Sets: Some pencils were paired with standard fountain pens in a single box and then combined with a ball point pen box. They were then paired together as a box set of three items.
Long-term collectibility / values: Montblanc pens continue to prove themselves as solid top tier collectors. Prices have grown since first sold, but full original boxes and paperwork are necessary to justify top values. Condition and usage should also be assessed. Prices l vary significantly between asking and sold. Many listed items on websites such as Ebay are often sold for 'best offer' which is not made public. However, it appears prices for high quality items with original packaging are commonly as follows (as of December 2022):
Standard Fountain Pen: ~£1,200 UK / $1,450 US
Limited Edition Vermeir Pen: ~£2,500 UK / $3,000 US
Ballpoint Pen: ~£700 UK / $850 US
Mechanical Pencil: ~£400 UK / $500 US
Set of three (incl. standard fountain pen): ~£2,200 UK / $2,700 US
See 'sold' items on Ebay or recent auction results for an accurate understanding of where the market it at any given time. Given the volume for sale at any time, pricing is very transparent. Long-term appreciation is unlikely to be more than inflation as pens appear fully valued.
I have a full collection never used if anyone wants to put in an offer