I would be honest with your wife if you can't be honest with her then you really have a problem. Let her go with you and see what you're drawn to, tell her although you appreciate their thoughtfulness that it would be better if they must give you something to make it the gift certificate/card. I am pretty sure she can then spread the word to the others. I had to do this with my sisters they couldn't believe I was having such a hard time just telling them!