I did a package with a company with red helicopters that lands by the river, you do about a half hour boat ride, then get back in the helicopter and fly back. So, hardly any time in the canyon. The boat ride didn't do much for me.
I know the Grand Canyon quite well and was disappointed with the landing spot, which is in the west Grand Canyon, which is only about half as deep as the National Park at the north or south rim. However, if you aren't familiar with the better spots, you would probably be impressed.
Discounts are probably going to be hard to come by. As I recall, the helicopters fit four guests.
If you've never been in a helicopter and/or have never been to the Grand Canyon -- go ahead. It is expensive but a trip you'll never forget.
Still, I think if you want to do the Grand Canyon properly, then pay a visit to the National Park on either the north or south rim.
It's not whether you win or lose; it's whether or not you had a good bet.