id say they were trying to get you to buy better rubber - yes, the falkens are midrange tyres, but in all honesty, the zed isnt that fast... maybe stick with the premium stuff on your m3s, RS4s and porsches and like, but 280 is less than some hatchbacks these days.
a set of four falkens would be about £500 fitted, and the difference between mismatched, on the limit, budget jobbies will be light years apart
i'd give it a go selling the budget tyres on ebay - although id make it very clear that these are sold as seen, buyer to inspect fully before buying, no refunds, if in any doubt dont buy.
I sold a pair a while back in good faith, but after the seller got them home his local tyre place said they wouldnt fit them, and so demanded a part refund - i gave it to him, but next time i'd have made it clear its a case of caveat emptor.