they are called qprox and are very cheap. qt-110 is a single (6 pin dip) ic that can give you a toggle switch for one function. they also have 6,10+ ic's that have error correction to figure which 'button' has the greatest capacitance change and just trigger that one.
i built and tested something very close to what you are talking about and it worked pretty well. if you are considering backlighting don't use 'el' wire as it screws with the ic. best thing to do is to get a spring as your electrode and put an led in the base of that. (this is if you plan on having a flat panel that lights up the 'area' that you want to press.)
with these 'switches' you dont need to actually touch the 'electrode' you just have to get close to it.
if you want a panel like shown above. get a piece of clear acryllic and spray the back black. then draw your buttons in adobe illustrator or similar package and send the piece out to a laser engraver to get the text etched from the back. then wire up the electrodes and leds like i had described and you'll be good to go. if you dont want the shiny look, then paint the front of the plastic and have the laser etecher just etch the front. i have a laser etcher contact if you need it.
cost...dirt cheap. the single qt-110's are a buck or so, the bigger ones are around 4 bucks, if memory serves me right.
oh..you'll need to make a regulated 5v power supply. just use a voltage regulator and cap.