Just wondering how others have handled the expenses and helping to pay? The reception will be in parents backyard. We are planning to meet with her parents soon but am still trying to get used to the idea.
If you can and want to help pay for the wedding, I would suggest coming up with a dollar amount that you have decided to contribute, then just tell your son, "We are willing to contribute $5000 toward your wedding" and let them figure it out from there.
When I got married, my parents and his parents each paid for the people that they invited to the wedding. My DH and I paid for our friends that we invited. My parents paid for everything that was 'my' expenses (flowers, gown, etc). The venue we used was all inclusive, that the limo, reception flowers, cake, linens etc. were all part of the per person price so splitting that stuff was pretty simple. Someone bought our invitations as a gift to us. DH and I paid for the honeymoon and photographer and my gown.
On the other hand, when my brothers both got married, they both married girls whose families couldn't afford to pay for weddings, so the both had at home receptions (one in my parents yard, picnic style, Mom and I did all the cooking, the other one at the Elks Club, my brother did all the cooking and food prep himself) and my parents paid for everything for both of their weddings except for the brides gown.
I think it depends a lot on the wedding, where it is, how big, what 'style' it is, etc. but you should pay what you feel you can afford. I think the old traditional thing about the brides family paying for everything is pretty rare these days.