Mei Tais are a cost effective carrier that can be used from birth to toddler. In the library we have a selection for parents to try. The beauty of a MT is that with the tie straps they are ultimately adjustable. For comfort it is worth looking at ones with wrap straps or with some shoulder padding. Many small companies produce MTs and they come in a stunning array of fabrics.
The Pod and Onbuhino are other Asian carriers to consider.