The unpredictability of auctions

Offered in Maastricht on 13-16 June 2014, est. 2,000 to 3,000 Euro: not sold.

Offered at same auction house, 26-29 September 2014, est. 800 to 1,200 Euro: not sold.

Offered at same auction house, 11-14 March 2016, estimate 1,000 to 2,000 Euro: sold for 2,700 Euro.

Now for sale at Hargesheimer, Germany, 24 September 2016: estimate 800 Euro.

Art really isn't an exact science.

UPDATE: sold for 1,700 Euro. Weird...