Co-give 

To split the cost of a gift between two or more people.

I only have $10 to spend on a birthday present; I'd better join up with my friend so we can co-give something a little better.

Co-give by Captain Nimbus June 6, 2013

Co-givers 

Two or more people who attach their name to one gift to save money.

We could each only afford to spend $20 on a birthday present, so we became co-givers to get one good gift instead of two crappy ones.

Co-givers by Captain Nimbus June 6, 2013