Contribution / EK / Majestic Scrolls for easier trading

People often sell their contribution, majestics and EK's to other guilds. However, this typically requires you to leave your current guild, join the new guild, donate the agreed amounts, quit the guild and re-join your original guild. On top of that, there's the sketchy part where you need to trust the counter party to pay or donate after you've already done your part. 

Some might say, this will entice people toward selling their cont/eks/maj instead of donating it to their own guild but I'd argue that if they're inclined they're going to do it anyway. It's on the guild to foster the desire from their members to contribute back into it. This is a quicker, safer, easier way to make these transactions happen.