If you've ever helped your friends move or have had them help you, you can weigh the economic benefit very easily. Not only does it strengthen your friendship,

If you've ever helped your friends move or have had them help you, you can weigh the economic benefit very easily. Not only does it strengthen your friendship, but it takes the profit margin of a moving company out of the equation - that's the economic gain your group gains (even after you buy your friends beer and lunches - you should still be in the plus)