I want to again thank everyone for their responses. On a side note, the electrician said the pipes need to be grounded because of this scenario: what if I was cooking, touched the stove and my ungrounded kitchen faucet at the same time, there was a chance of getting electrocuted. Needless to say, it did scare me.
That wouldn't/couldn't happen. Your stove is already (or should be) grounded, so you can't get the frame of the stove to be energized. In the other way, the only way that the faucet could become energized is what I mentioned before: some damaged wiring somehow makes contact with the metal piping. It is a long shot as the damage would have to be right where the wire crossed the pipe and the pipe would have to be touching the wire. Bonding the plumbing would prevent this, but I really wouldn't worry about it.
In my case, I bonded, but for several reasons:
1. metal pipe coming into the house and using it as a ground rod
2. easy access during basement reno
3. did the work myself, so the only cost was a bit of wire
In your case, it looks like he is trying to make some money off of you.
Again, thanks for the reply. The scenario the electrician gave me was in answer to my question of: "how do my copper pipes become energized". That's when he talked about the stove. And yes, this guy is licensed--I looked on the state's website.