WOW - the restrictions your family puts on makes it rough.
How about a tie-together fleece blanket? My sis-in-law made one for us a few years back and I have to say it is likely the MOST USED gift we have ever received.
If you don't own or can't borrow the materials (material cutter, measuring stuff) it might put you over the $30 limit though. But if you know someone who does any sewing - you could likely borrow. Then you'd just have to buy 2 fleece pieces of material. WIth a 40% off coupon to Joanne's for each you should be good with that. Or - just buy a fleece blanket - nice ones at Kohl's for $20.
For a grab-bag guy/girl thing for my work people - I just got a car care kit - Amor All stuff. But you could go one better and get an emergency kit for the car (I just saw some at Penney's).
A nice welcome mat is usually a good thing to have or replace if you already have one.
A greeting card package - a couple of boxes of cards plus some stamps, maybe some fancy envelopes.
A nice new duffle bag or rolling carry-on bag.
A travel 'toilettries' bag - with 3 ounce containers inside to fill.