When I fabric shop I have to pack a lunch, it is a day trip of sorts. So I usually go when I have a little more money. In December, I spent about $150 (also bought some quilting hoops). My quilting group is planning a minor road trip this Friday, weather permittting, and a more extended one next week, weather permitting. I have been buying fabric for this year's planned projects, so I will only have to add a piece here and there to complete/enhance projects.
Normally, when I go I usually purchase mostly fabric I like and less for a specific project. I find that if I always buy what I like, it all tends to work together. Where I usually run into trouble is when I try to follow pattern recommendations. So after a year of trying to follow the pattern reccommendations,I have reverted to only buying what I like and making project selections from my stash. Works much better for me.