I also agree with sending SS favorites, because my favorites may not be someone elses choice. However if we do this, I would tend to be very general in what I send, so my SS would end up liking what I get her.
Also, I do tend to overspend, I like the min/max idea. Perhaps $10.00 minimum and $20.00 maximum? For the last month, $15.00 minimum and $30.00 maximum? So it at least gives us some room. This would be including shipping too.
I also like the idea of specific questions. Like Buffy said, some of the people I know what they would like, but if I got someone who I didn't know, then I would be in trouble if I only had general questions!!! It just makes it harder to shop for that person. Also, we should all try to be as detailed as possible to make it easier for your SS to shop for you!!!! I remember one time, i got really general answers very non-specific and it just made it very difficult to shop for that person.