Does it (plain, flame, veneer) sound different? Does a blue guitar sound different than a red guitar?
Depending on the manufacturer a flame/quilt top can cost you hundreds more. Sometimes over a thousand. This is for a solid piece of flamed wood though. Not veneer. Veneer is usually only a little more expensive, if at all.
The lure of flame/quilt is that someone tends to look at the guitar and without ever touching it say, "Wow! What an awesome guitar!" The impression is that it is better when in fact it may only look better. At least most people like the look. Some prefer plain or solid colors. But they're wrong...
