In cases like these the golden rules of pinball transactions comes into effect -

If you have the means, inspect in person before you commit to buying. (Even better write the trip off as a work related tax deduction and get a nice holiday through the rest of Europe as a side jaunt at the same time.  )

Don't focus on one or a set list of machines, hand pick the roses amongst the thorns and go from there.

The asking price is rarely if ever the actual end selling price.

People are always more conducive to negotiating a better deal face to face rather than back and forth emails.