I suppose it depends on what the difference between the two is? I bought the top of the range Blue Seventy a few years back, and the reason for that was that I thought it might be worth getting that thinner neoprene around the arms. I hate swimming in a wetsuit (although I love mine), because I feel that the suit restrains my natural swimming movements (maybe I just swim strangely), and so I decided on the more expensive version due to its supposedly more flexible fit. You should take a look at what differentiates them, and then decide whether it's a feature that is important to you.
Think orange. Earn success.