What would you charge for a 3D Electric Guitar Cake? I have someone wanting one and I saw all the wonderful ones in the gallery. Any ideas?

Depends on cake pricing in your area, how large you want it, fondant or buttercream... etc.

I just finished a two layer one (posted photo in my gallery tonight), and with all the cut edges it was a monster to crumb coat...but it was for my DS BD!
If I were making one to sell I probably wouldn't do it for less that $60-$70. This one is on a 14" x 20" cakeboard, so it was pretty large. HTH