Guild prices are not affected by fame, they're affected by past sales. When people buy up a lot of all of the guild's stock of an item, when it becomes available again, the guild raises the price. Arrowwood lumber can be as cheap as 3 gil per piece at the guild if no one buys any for an entire game week.
I would like to thank Greta for putting these up in San d'Oria AH for 1k a stack. I buy them and resell for 2k a stack and they sell fast. I don't even have to log, synth, farm, buy crystals or twine or do anything but stand there and I make more gil than you on the lumber. Thanks again ^^
On odin w/ max fam their about 18gill each at guild shop.
Problem is the sell out very fast. So you either have to make your own from logs which is time concuming at best, or spend more and buy from others.