I too stick to the $20 limit plus the 4 FQ, and of course their favorite candy; so total I am spending about $35 because I do buy my FQ's at quilt shops so it is good quality fabric, which is my choice. If I had a picture of the box I sent I would post it, but I didn't take one; however, I am sure my recipient thought I spent a lot more.
I begin making things for the next years swap right away. In fact I have a couple ideas of things I want to make for my swap partner next year so over the holidays I will probably begin my 2017 box. I always have used patterns and magazines laying around so those go in the box and are considered stash by my book. Any fun fabric that my SS likes that I have in my stash, send it. Also, I do the monthly SP swaps and sometimes I received things that I may already own, or know that I will never make myself and if I feel my SS would like those in the box they go. The one thing I do do is make sure all items are in excellent to new condition. I would never send fabric that had an odor to it or discolored. Also, I look at things to make sure my SS would actually like it and not just clean out my junk drawer.
This year there were a couple handmade items I had in her box that was on her color dislike list. Guess what, I did not send them and only had enough time to remake one of them in colors that were to her liking.
I feel it is important to remember the true spirit of this swap and that is to have fun. I have fun putting together a box for my SS and to me that is all that counts.