How about a "Help me out here" button. Let's say an upgrade costs 5 million, and I've got 3/4 of the resources. I want to be able to set aside my money for that upgrade, and then hit "Help me out here" to get resources from alliance members. This helps in two ways. First, if I run out of time while trying to farm for an expensive upgrade, my resources are no longer at risk. Second, I frequently find I have 500k+ resources left over after I log off, which I would happily donate to an alliance member if they had a "Help me out here" request going. To limit this perk, you can only have one upgrade going at a time thanks to "Help..." and you must have something like 3/4 of the resources put down towards that upgrade before you can request.
This would also be a huge bonus for newer players joining their friends. As an IA player, it costs me nothing to help a Classical player with their resources. This helps newer players catch up to their more experienced alliance members.