I've shipped my boat (rubber, frame, boxes, groover, oars, etc.) from Anchorage to Salt Lake a few times with FedEx ground. Usually runs me around .4$ / lb. Have to be a known shipper though...not sure how that works now.
Note too that you'll have to donate your repair kit adhesive (HazMat) unless you want to try and placard your boat.
Just have it broken down, well protected, and well labeled (we did have a dry box full of sleeping bags and oar stands end up in Minnesota before a trip).