Poland negotiation style's or techniques
My dad loves this type of thing. He was very much into 'contra deals', which was he would do something that he was good at (graphic design/artwork) in exchange for something else (goods/other services). This type of 'negotiation technique' was shared with his smal circle of Polish friends too so I think it may be a Polish character trait (he had quite a few Aussie and Lebanese friends who he brought into the fold as well). It probably would have been better to have been paid money for his professional services because the stuff my dad used to contra deal for was typically junk and/or an item that he thought he could do a contra deal on in the future!!
I was oh so happy the day my dad gifted me a 1970's style Farfisa keyboard which he contra'd for designing a business card.
I think your understanding of the word 'barter' is misconceived champ. Even if it was correct, how does a preparedness to barter indicate the possibility that Poles are sometimes wrong? I for example love to barter and I am rarely, if ever, wrong.
be prepared for the unexpected.
Too true mate, too true. If by the unexpected you mean for example going to buy a car, 'test driving' it for a week, then returning it, asking for another car for another week, then deciding you want neither nor did you actually want to buy a car.