Playing Guild Wars with my brothers?

So my brothers and I all chipped in to get all three GW games and we are all addicted to them. Only problem is that you can't reuse CD keys or be on the same account. I've been searching for all three games at a decent price, to no avail. At Amazon.com there was a Trilogy box, but it was, and still is "currently unavailable". I think this would be the cheapest way to get all three so if you know where to get one of these boxes, or know of a better way to be able to play with my brothers, that would be very helpful. Thanks!