IMO opinion I dont like the idea of being invited to a wedding and being asked to pay for the meal, regardless of whether gifts are then expected or not. But mind you I am a bit of a traditionalist in some things.

I think use the $3000 to pay for the meal and get everyone to pay for their own drinks - maybe just provide juice and or soft drinks. Cause as Ashlee also said
And then what if the tab ran out, which it most certainly would (people take advantage of an open bar).