The novel you were thinking of is The 34th Rule
, and it was coauthored by David R. George III and Armin Shimerman, the latter being the guy who played Quark.
I also recommend Worlds of Star Trek: Deep Space Nine
Volume 3, which contains two short novels, one of which is a Ferenginar tale by me called Satisfaction is Not Guaranteed
In addition, David A. McIntee will have a novella in next year's Seven Deadly Sins
entitled "Reservoir Ferengi." That'll be out in August.