I can tell you they fill up insanely fast I started a fresh one recently for some friends and it had 50+ applicants in an hour. Personally I don't like to charge fees or donations id rather everyone invest in there accounts and have more to donate by choice when there killing it later on but some guild do require fees or donations every month/season so if you go that route as a leader they can bring in quite a bit of dec. With the addition of guild brawls and gladiator cards more people want to join for those bonuses as well and are willing to pay a reasonable fee.

That being said the fee to actually get started is the guild for 10k then another 30k for all the important buildings to get brawling 40k if you count the barracks but you can put that one off until later. Even after that investment a fresh guild is not likely to do well for there first few brawls so it will be slow to earn rewards at first.

If you can find your way into an established guild you can skip the build up period and start earning packs at a reasonable pace the issue here is these spaces are fairly competitive. Right now it seems there are many guilds with a lack of players who either own or are willing to rent to fill a gold fray every 5 days if your looking to try and join a guild it could be worth looking for one with a high but not 100% fray fill rate and offering to fill there open fray slot.

Personally I went the own guild route and im having a blast and now manage 2 guilds but they take some time and that route is not for everyone.

apologies about the book but I hope you find some of the info helpful