I'd give different people different amounts, but I'd only give what I could afford.
I'd always rather give people money and we asked for money when we got married. Wedding gifts were traditionally for people to set up home but most people are already living together and have household items. Money is appreciated a lot more. You're always going to get people who object but I don't see why. When we got married one person didn't give us money (she's known for being awkward), she bought us a few bits and bobs including a picture frame. She probably spent about £20 but everything she bought was horrible, it was exactly to her tastes but not ours. I don't even know where any of it is now, it's probably under the bed in the spare room. Surely that's a complete waste? I'd have appreciated a single pound coin more than that.