Aside from telling you to stay away from Niterider (I had a real scarry ride down a steep hill in total darkness thanks to that system quitting when I most needed it, one of many problems I had with the system), The advice I'd like to give to anybody about purchasing a lighting system is this:

Do NOT let a high price tag deter you. I should have purchased the great and expensive (Lupine) lighting system I now use right from the start rather than pissing away money on multiple crappy lighting systems that didn't do the job and ended up being faulty.

By the way as part of your price comparison, don't forget that some lighting systems require mounting brackets (unlike Lupine), so if you want to quickly switch your lights to different bikes, add in the cost of extra mounting brackets. The price of those "inexpensive" systems tends to rise quite a bit when you do this.

Think about what would happen to the lights mounted with a fixed mount if you crash and how are you going to feel about removing and replacing the lights each time you lock up the bike outside. How the lights are mounted on a bike matters a lot.