its not as expensive like what was written. The gr 20/33, vg-8/88 has been out in the market for more than 5 years or even longer, depending on which product. The price is still not cheap, but not as high also as written.
anyway, putting the price aside, the triggering of the piano tone from guitar is really not suitable. i have the gr 33 for couple of years. The piano patch is one of my LEAST favourite. All the nuances of piano characteristic is sorta lost when you wanna trigger the piano notes by fretting guitar and plucking notes. Either the piano sound will sound too abrupt and harsh or half fckued sounding when the midi pickup aint picking up enough of the strings vibration to trigger off the piano sound from the module.
For piano sound, it aint working well imho. But other patches like saxaphone, flute, keyboard synth sound, sound effect and trumpet etc, still can fake way thru and better sounding than most of the piano patches in there