It's all about composition and construction.
Composition: Your wood source will determine price, your hardwoods such as oak, maple, cherry and birch are generally stronger and more stable and price is higher for these reasons and the fact that they are less available. Softwoods like pine and fir which will generally dent or scratch easier than your hardwoods and are more available tend to be a lower price. Your maple and birch furniture will often be more contemporary with simple lines as these woods are harder to craft but they take stain very well and are resistant to warping and shrinking and swelling. Your cherry is often a veneer, and although this usually has a negative connotation, the cherry veneer can offer an elegant look and longevity when paired with a high quality base material.
Construction: This is the difficult part because it is tough for us to be experts in wood craftsmanship and unfortunately very easy for some manufacturers to make the appearance look so appealing that we forget about what's underneath. But as I did with my first grade 8 crush, let me list some pros and cons to look for in the construction. Keep in mind this is based on looking for longevity in your purchase, if you are filling a spare bedroom some of these things may not matter to your purchase.
- Staples, if you see staples it isn't crafted well.
- Exposed glue, probably quick assembly was more of a concern
- Jostle the piece of furniture, if it squeaks, rocks, twists or wobbles it should be reflected on the price tag.
- Knots or cracks, some desire the rustic look of knots but they still should be finished well.
- Particleboard - if you see this anywhere, it splits easily and veneers pop from it eventually
- Edges don't have even, consistent stain like the tops
- Look at the interior corners see if there are corner blocks that attach at the corner
- Product with drawers, look for thin sheets of wood between the drawers (often called dust panels) these add stability
- Back panels are flush and fitted and are screwed to the frame.
- If backs and undersides are stained and finished this is very high quality, reduces chance of swelling and shrinking even more.
- Doors/Drawers are aligned, indicates sturdy structure
- Smooth even feel as you glide your hand along finish, even the rustic look should feel smooth without blemishes or rough patches