Those are really good suggestions sweetichick, and otherwise might be useful, but I think this time I am really going to need to learn to stand up and say no, so the only way is to directly deal with it.
The vacuum cleaner, oh my god, I would have actually bought the damn thing, there was nothing it couldn't do. It was the best thing I have ever seen and a legitimately exhilarating two hours of my life (um, I suppose that is saying a lot about my life, and not good things...) I was like "SOLD!!!" and he said "ok, that'll be €3800!" I was floored! i honestly had no idea that a vacuum cleaner could cost so much. No idea whatsoever. I knew it would be expensive but was so impressed by it I was even willing to stretch my budget, thinking at max I'd end up spending, oh I don't know, €400, €500. When he told me the price I could not believe it. You can buy a used car for that much money!