As a "specialist teacher" I don't expect anything from students and I think most specialist teachers are very surprised when they do get something. I probably won't give anything to my daughter's specialist teachers simply because it isn't in our budget to do it. We already have 6 Sunday school teachers, 2 daycare/preschool teachers, and a gymnastics coach to give to.
When I have gotten something it is usually a couple pieces of chocolate, a fancy hot cocoa packet, an ornament. I don't think I have ever gotten a gift card or anything like that since I became a specialist teacher.
Last year during teacher appreciation week I gave all of our daycare teachers a s'more kit (1/2 chocolate bar, a graham cracker broken in two, and a marshmallow) with a note that said, "Thank you for all you do. We couldn't appreciate it s'more."