I think it is the implication of being "told" what to give which is where the wishing well comes unstuck. At least with a gift registry you have a choice in gifts and can make it as personal or impersonal as you like.

Regardless of whether you were planning on giving cash or not when there is a wishing well it is almost like the choice has been taken away from you. I like to be given choices and resent being told what to do.

In my European culture a lot of the older people will give cash and that's ok...that is their choice to do so.

If I am going to a wedding and giving cash I would give $150 for DH and I. If it was a sibling then $300-500 and a close friend $200.

Incidentally when we got married back in 2001 we had 220 guests. Total wedding cost was around 27k - this was split between the inlaws, my folks and us. We received around 6k in cash at the wedding which we then used to purchase a larger wedding photo album and some photos for the wall which we would not have been able to otherwise afford.