If one is really not that close to the couple getting married/barely sees them/no Christmas cards sent between the parties, etc. etc. - one, they should not have been invited in the first place and two, as a guest, I would not feel bad saying no to the invite. Not going for a free/almost free meal. Why would I go? It would still cost me money.......a dress, hair done, maybe a sitter, etc. etc. No.......if we are not close enough - no need to be invited.
Northeast here also. People or some people/family members do try to "cover the plate" but I think that mentality has gone out the window too because wedding costs a ton of money/out of control and one cannot expect someone else to cover their expensive choices/wedding, etc.
I still would not attend a wedding here and give less than $300. This is what it is here. Gifts are for bridal showers and money is for weddings. I respect and understand that it's not the same everywhere. Example, we (and not just hubby and I, more or less people where I am from) give $100 for graduation in a backyard (family). Maybe $50 for a birthday - at the house.
At the end of the day, even if you are a close member of the couple, one gives what they can afford.
If I was not attending for whatever reason - I would send $50 - $100.
Have fun!