All of the above +1.



But to answer your question, the low-end Martins are frequently made of HPL (High-Pressure Laminate, or 'Plywood' as we old codgers used to know it!) and not from 'solid wood'. Plywood is a much cheaper material than, say, solid rosewood or mahogany. That's not to say they aren't perfectly good guitars, they very much are - but they won't 'open up' as they age, and they don't ncessarily have the same quality of finish as the Standard series and above (18 upwards).

There's more to a guitar, however, than appearance, and how much you want to pay is up to you, no-one else. So get round as many dealers as you can, and play as many different guitars as you can, and buy the one that feels, sounds and looks 'Right' for you at the price, irrespective of the name on the headstock.