Hey guys, I made a quick tool to help you find out if you are paying too much for membership in a trade guild. If you are, you should at least bump your sales up to the numbers you output in 'Break Even'. It is also useful for helping GM's to make decisions about their guild finances. The file is called GT&F and is safe to download. If the link is broken you can find a hard copy on our guild website here. I hope it brings you some easy insight.

http://www.filedropper.com/gtf

In the guild trader bonus a general guide is to set the trader bonus to:
10% for an out of city guild trader
25% for a normal guild trader
50% for a premium guild trader
note that these bonuses I gathered a while before B2P, so they are probably different now. I estimate it to be more like: 20%, 50% & 70% now and 15%, 40% and 65% before imperial city. However its all really case by case, some stock will move just as well with/without a trader.
Enjoy
ps. Let me know if there are any changes that you might want to suggest ;D