I wouldn't pay to have the mod performed, but I have heard modded equipment sound better than much more expensive gear. Not all the time, mind you, but it does happen. I bought a Marantz SA-11S1 that had a $3200 mod by pcX done on it about 7 years ago on Audiogon. It sounded better than two more expensive CDP's I owned at that time, so I sold them and kept the modded Marantz.
7 years later, it still sounds great. I keep it because it would only bring me $1500-$2000 in return, but I'd have to pay over $5000 to beat it sonically. No matter what the glossy rags would have you believe, technology has not changed that much.