Can't think of why I didn't post this before ...!
My guild started a Quilter's Day Camp four years ago. The first year it was five days (M-F) of half- and full-day classes taught by our guild members. The price was $15 per day, MEMBERS ONLY, which included classes (taught for free by members), lunch, beverages and snacks (baked goods, fresh fruit, fruit salad, crackers, cheese, etc.) and desserts. We had donated baked goods and chocolate (!), and people generally shared what they wished food-wise. Meals had at least one hot thing, and were prepared by members of our guild.
Classes were whatever someone wanted to teach, and classes went forward even if only two people signed up for it. Anyone who wanted to come sit-and-sew was welcome.
The second year, we cut it back to 3 days. It is still wildly popular and the next one starts in a few weeks. I am teaching a purse class, and another to make Quilt Block Clocks, using Lynne Koolish's book as the reference.
We decided to have Day Camp rather than a retreat because a retreat usually focuses on one pattern or project. This way we had an across-the-board-selection so everyone found something to be interested in. In theory, a person could get six half-day workshops plus lunch for the grand total of $45.
PM me if you want to know how we set this up, lessons learned, and anything else.