I'm not going to debate about the price difference. If people are willing to pay that, so be it. I think the Elite Rings are worth much more than their cost. From what I hear, the TRX is a well made and well packaged product. But it doesn't really work for the type of training I do and recommend for others. The main problem is that it has a single point of attachment. This means the straps come up at angle in towards your head. So when you are in a support position, it's impossible to keep the straps off your arms. It also means that your feet must be on the ground, otherwise you start spinning. Also, the two handles are not secured in place. They can slide if you put too much pressure on one side.
These points are pretty clearly illustrated in this muscle-up video on YouTube:
http://www.youtube.com/watch?v=AtWV9lrGr_M
The thing about them sliding shows up after the fourth muscle-up. That's very dangerous and I wouldn't recommend it for beginners. The guy in the video is obviously strong, but he still doesn't lock out because the straps are too narrow at the top.
There are a lot of cool exercises done on the TRX and some dubious ones. But you can do most of them, except curls (!), on the Elite Rings. Andrew Stemler wrote a pretty cool training guide showing some exercises on Elite Rings that are similar to the TRX foot strap exercises:
http://stemlerfit.com/page18.htm
Just click on the link for the "easy ring training guide". He did an outstanding job writing the guide. He shows that most of the exercises can be done just by placing your feet on the rings.
Anyways, I'm not bashing the product or the company. It is better than 99% of the fitness gizmos out there. But you can't get your feet off the ground and that is most of the fun of ring training. So, in conclusion, why not buy 2 pairs of Elite Rings?
Tyler