Blackburn-based First 4's managing director David Nestor said that a wily salesman at used equipment supplier Grafitec had left a message on his Facebook page tempting him to make the investment.
The company spent £300,000 in 2008 and aside from one or two investments since, including an ST300 late last year, First 4 had not intended to bump up its stitching firepower.
Nestor said: "We weren't on the lookout at all but the machine only has 100 working days behind it and we picked it up for a fraction of the price for a new machine.
"He posted on my Facebook page 'do you want to buy an ST400?' and I said 'no too expensive'. But he put a deal on the table that I couldn't possibly say no to."
The machine replaces a Heidelberg 705. Initially the company bought the ST300 last year to replace the 705, but due to an increasing workload the ST300 ended up operating as an additional machine rather than a replacement.
According to Nestor it is a "huge leap forward" on the 705. It runs at 14,000 sheets per hour, which is more than double its predecessor. He added: "As well as its speed, the makereadies are automatic; we can go from A4 to A5 in 20 minutes. This is a big leap forward for us, it really bolsters our firepower. We can handle in the region of 2-3m A5 books a day now."
