The didge forces you to learn circular breathing, it's cheaper, it is easier to learn, and is easier to play well. Plus I think it sounds better. Everyone should learn to play the didgeridoo. Bagpipes are a whole another level, and feel more like a practical joke gone horribly wrong (Sorry Gran.)
In the case of the Great Highland bagpipes, the most similar traditional instrument is the rauschpfeife (capped double-reed with conical bore and without prominent bell):