I agree with Eddie that certain elements of a wedding are fixed costs, ie dress, suits,flowers etc will cost the same regardless of the number of guests, while the meal/wine cost is really the only variable. Its a bit late coming in with 3 months to go as most of the big expenditure is committed to ie hotel, dresses, band etc.
That said it was a bit idiotic imo to tell the couple to invite more guests in order to get more cash gifts..and then for Eddie to tell them to ask for cash only
..its just not the done thing and while I would generally give a cash gift I would take offence if asked for it.
Relying on cash gifts from guests to pay for your wedding is a foolish thing to do. Just to shoot Eddies theory down in flames we found that some guests are incredibly generous, some wouldn't cover the cost of the meal/wine and some guests give nothing.(and before I get flamed for that comment I mean it as a way to show the fundamental flaw in Eddies thinking...it didn't make a blind bit of difference to us)
We wouldn't do anything different. We had some pressure from our parents to invite certain people so as a compromise we gave each set of parents X number of friends to invite...and they could choose who they wanted there.
We kept costs down as much as possible and only splashed out on one thing...the band. But as we are both big music fans it was important to us. In total we spent about €11K for 70 people...my Dad insisted on paying for the meal and got quite insulted when we initially refused. The balance we paid for from savings. Neither of us would have been happy getting into debt for one day....and we certainly wouldn't have got married without having our house first.