I don't like being tricked and it has only happened once that I am aware of.
However, with my OH, I have pulled the cheaper option on some things cos "if can't taste the difference, don't pay it". But all swaps were something he was fine with it the first place that wasnt going to make him unwell,
Yes, of course, the tomato sauce is Heinz, not Asda smart price, that pasta is napolina not smart price, the blackcurrant cordial is Ribena of course as I put the cheap bottle out of sight or decant to branded bottle. I use a lot of own brand value range stuff but if when he eats here he had the slightest bit of problem that would change as needed.
He can sometimes be a brand snob at times but I wouldn't change anything major that would make him ill or put either of us at risk.
Although I admit the cheaper stuff is transferred to the branded packaging so he doesnt have a psychological mini shock. He knows it happens but we don't mention it.
He loves a dip to go with tortilla crisps, his mother makes which is basically a mix of fresh tomato salsa, chopped spring onion mixed with mayonnaise. His mum gave me the recipe as she has been making it for him since he was a child, the fact is he doesnt like mayonnaise and will turn down food if it has mayonnaise on it, so she passed her recipe to me, we agreed not to tell him nor are ever planning to tell him, the dip is 75% mayonnaise which he doesnt like. It's a secret recipe. 